get real, RMP is faceroll and that's why it's the #1 3v3 team since s1
the main thing is all the control they have and all the abilities they have....sure, you have to know when to use what but 3 competent people can make it work easily
it's not the easiest comp but "high skillcap" is ridiculous
we all know what the other guy is gonna do, we all know how to counter or when to eat it and we all have hard counters...except mages, there is no hard counter
you control casters and melee, you have a passive and multiple active ways to get away from people (caster or melee, doesn't matter) and you have burst
nothing a mage DOESN'T have at their disposal