The revolutionary army is weak and remained weak even after Sabo became number 2. I can see Kuma as a TOP TIER in his PRIME, considering he was the unbeatable champion (slave), and the revolutionary army can indeed have 2 TOP TIER, maybe even 3, because the minimum expected for an army whose cause is to overthrow the government... I think Kuma in his Prime could be in the Mid Top tier.
Damaged, with a dull rationality, and programmed only for tasks, at this moment, he can't even defeat Jack; he urgently needs repair.