This bug has been known to be a bug for a few years now, since it directly contradicts Classic behavior where a player can be affected by both totems and blessings at the same time without either overwriting the other (in other words, it works exactly like it does in TBC, where the only buffs of the two classes that conflict are Resistance Totems/Auras of the same resistance; that's it), but it never got fixed on vMaNGOS until fairly recently since it didn't really matter; there weren't any servers that had cross-faction capabilities.
Now that there is such a server in the form of Turtle WoW, though, the bug has caused a myriad of huge problems for both Paladins and Shamans, and even players who don't play either of those classes will have no doubt noticed the annoyances it's caused in both raids and any sort of dungeon with both a Paladin and Shaman in the group. Paladins just aren't allowed to use many of their blessings at all on melees who are in a group with a Shaman in raids, and in dungeons, Shamans are pretty much forbidden from using almost all of their totems. But the Turtle team has been extremely adamant about refusing to fix this bug, for a full year now at this point, with the main reason being that "it would make Warriors too good with WF + Might + Kings."
To address the fallacy right away: contrary to what many, including the devs, might first think, Warriors could not give less of a damn about the blessings in raids. All that not having blessings in raids does for them is make their hollow dps meters look a little bit smaller. The only class that's really affected by this is the Paladin, as the DPS increase caused by Blessings was provided by the Paladin in the first place, the Warriors are merely the medium that much of the Paladin's contribution to the raid is going through; they're balanced in a raid environment around being able to contribute those support Blessings to the raids, unlike Warriors or healing Priests who focus on raw DPS or healing. The same goes for the Shamans, and I'll get to them later.
The game in raids wouldn't get any easier if Warriors could use both Blessings and Totems, because either way a Warrior in a complete meta environment could just replace a third/fourth Paladin and provide far more raid-wide DPS, or have any other class replace either the Paladin or the Shaman in a dungeon group with both classes and still provide the same amount of effectiveness in terms of damage, healing, and/or utility (and interestingly enough, the devs did fix the Ignite bug which caused Fire Mages to output far less dps than they otherwise should've, which actually did make many of the raids much easier by fixing it). All that not fixing this bug does is cause both Paladins and Shamans to be able to contribute far less to their dungeon and raid environments, being one of the only instances in the entire game where classes are directly making each other worse in a group environment, actively discouraging teamplay between those two classes, something that no other class in the game has to deal with at all.
Now to get onto more big problems this bug causes:
- Shamans are completely throttled out of using their basic kit in dungeons. If a shaman gets into any dungeon group with a Paladin in it (which is most groups, because a much higher quantity of people are playing Paladin on this server compared to other servers), then Shamans are completely locked out of using most of their totems in dungeons. As a matter of fact, until they hit level 32, it's literally ALL of their totems except for their Fire Totem, because a single Paladin can buff everybody with either Might or Wisdom and provide far more than the Shaman ever would be able to with Strength of Earth and Mana Spring. And even when they hit level 32, they only get to use their Windfury Totem. "What about Stoneskin?", you may ask. Unfortunately, that's a no-go as well, because not only does it override Blessing of Sanctuary (a vital buff for the tank if a prot paladin with it is in the group), but it also overrides Devotion Aura, an aura that provides more physical damage mitigation and is the most useful aura in a dungeon setting in most situations anyway. So the Earth Totem slot is rendered obsolete, and the Water Totem slot isn't used in dungeons either because the next best thing (Healing Stream) is bad enough that it's just considered a waste of mana and a GCD. Most Enhancement Shamans I've seen while leveling don't bother with the Enhancing Totems talent despite it otherwise being really good since it's rendered obsolete in the vast majority of dungeon groups, and I shit you not, I've seen paladins who haven't even learned SoE or Mana Spring Totems at all while leveling.
There's been quite a few people I've talked to in game who have said that they outright chose not to level a Shaman specifically because of this bug. Dungeons were already infuriating enough to deal with in many groups even as a Paladin trying to work around this infuriating bug with my blessings, spending minutes trying to sort out which blessings to use and which totems to use so thatt the Shaman doesn't accidentally remove multiple better buffs off of everybody in the dungeon and it's so much worse as a Shaman since totems are a far larger and more impactful part of your kit than even Blessings are for Paladins. If losing out on Blessings as a Paladin is like losing out on Shadowform or Moonkin Form as a Shadow Priest / Balance Druid, then losing out on Totems as a Shaman is like losing out on finisher abiilities as a Rogue. And considering how little supply there is for Shamans despite the mass demand for them in raids, having anything like this bug that discourages people from playing Shamans is just absolutely terrible for everyone involved
- Ret Paladins are actually worse off on this server compared to Classic. Hell, if this bug doesn't get fixed by the time 1.15.2 comes around, they'll still be worse off even with all the new fancy shmancy changes. Why is that, even though they have Holy Strike, even though they can take advantage of Windfury Totem? Because for all the flaws that Ret Paladin has in Classic, at least they could give Imp Blessing of Might or Kings to the raid. Much of why they're balanced to be worse DPS is because they're support DPS; what they lack in personal dps, they (somewhat) make up for in improving raidwide dps with their blessings. Now, they're just worse warriors in every department, since all the melee support they could've provided to themselves and all the others is completely stripped away due to the bug. There's no reason not to take another Warrior over a Ret Paladin now.
- The issue of Shamans not being able to utilize their totems continues in raids as well when in caster groups. Of course, due to the lack of shamans on this server, there aren't even enough shamans to be able to cover all the melee dps much of the time, but a Shaman in a caster group can't offer anything due to both Mana Spring and Tranquil Air being completely dead totems due to Wisdom and Salvation being strictly better. It's literally the scenario that Shamans have in dungeons all over again in raids as well. We could've had an interesting niche for Elemental Shamans where they could've buffed the threat reduction of the casters alongside Salvation (and perhaps have lessened the issue of mana for the caster off-specs where going oom is a massive issue), but alas, that can't happen because of the bug. There's no point in even speccing into Mana Tide as a Resto Shaman, let alone Restorative Totems.
- Shaman tanks might actually be able to stand somewhat of a chance in raids if they were able to actually be able to utilize Paladin buffs at all alongside their totems. If they could actually use Stoneskin, Sanctuary, and Devo Aura all at once, if they could actually use Blessing of Kings alongside Grace of Air Totem, then they might actually be able to tank fights like the BWL Drakes. But unfortunately once again, because of the bug, that's not going to be able to happen.