I'd still take the whm+war combo over an all dps team. There's just too much utility between the two to cause so much disruption for the opposing team.

Also, its not that BLM and BRD are too weak (I can't comment on DNC, I haven't played it), its just that the lack of proper matchmaking makes their weaknesses stick out a lot more. A BRD LB doesn't have a heavy impact in a fight and they are heavily reliant on the team because its a support job that doesn't really have any burst. If you focus fire the target I just marked and silenced then ya BRD is strong as hell. Outside of that? lol good luck. Same with BLM. Their fire rotation is worthless, don't waste your superflares on it. Ice though? Hoooo boy they can cause some serious disruptions.....problem is that can't move while casting so its easy to just get away from them and God help them if a melee dives them. Their sleep is also....just meh.

Neither BLM or BRD are bursty and rely heavily on the rest of the team to peel for them and focus the targets they are controlling (silence/freeze). Less so BRD because repelling shot is pretty decent, but BLM is pretty limited on their ability to escape.

Basically when matchmaking decides to stack a bunch of casters....you're gonna have a bad time because no one will really peel for anyone as they are too busy running away themselves. Matchmaking should at least attempt to find a balance of melee and ranged between each team instead of just stacking all of one or the other.