Commander Overall Performance Tier List
This is based on my experience in 7 years of Coop. Thousands of hours of play and observation. I considered this mostly from how the commanders felt in terms of ease to play, efficiency, and the amount of micro/macro needed to fully utilize their potentials.
Just some personal notes. Am curious to know what y'all think too.
Mengsk A tier: Even I am biased because Space Stalin is my favorite and I play him religiously, I wouldn't put him S tier. Suffers from a lack of mobility unless you split your army, and his trooper army is squishy as it is unless complemented by royal guards which are heavily gas dependent; and royal guards are difficult to replace.
Raynor B tier: Definitely not beginner friendly, requires World-championship-level micro/macro, squishy and requires you to constantly train units.
Artanis C tier: Easy to play, guardian shell is a literal lifesaver, but his army always seems to disappear. Suffers from Raynor's constant training of units, mass tempests will win any map but they take forever to build up.
Alarak A tier: Alarak would've been S tier, but there's just something missing from his kit. I would say A/S tier depending on the prestige. P3 definitely S tier.