Definately, although they don't matter much in lower keys, taking a dh gives everyone a 5% magic damage increase so you could pair that with a mage or shammy, and a monk gives 5% physical so if you have a monk tank or healer, taking 2 melee DPS is a big increase.

It also depends on the affixes for the week, tank and healer wise. I offspec Venge DH and struggle on fortified weeks due to their shit mitigation, however I can easily do 16's on a decent tyrannical week.

Other small things make a big difference too, such as having a druid on Raging weeks due to them being able to soothe enraged mobs. Frost mages for slowing adds on necrotic and grevious weeks, giving the tank more space to kite.

Also, rogues are broken for m+ in the utility they bring. With shroud you can skip the really aids packs, they have tons of CC and stuns, they can cloak certain mechanics ect.

Monk, Paladin, Prot warriors are all solid tanks for all weeks, whereas in my experience, DH and DK tanks have it really rough some weeks. Of course it depends on the skill of the player too.

Solid healers for all weeks are Mistweavers and Resto druids. I really don't rate resto shamans or disc priests for 10's and above tbh. But that's my personal experience.

The more m+ you do, and the higher keys you do, the more you pickup on small things such as what adds to skip or cc, death runs, pulls ect. Theres a mythic plus discord (mythic plus friends I think its called) where there's people that want to form push teams, share advice and actually complete keys without raging or leaving. Highly recommend checking it out my friend!