Erm. If you use word “strong” it has nothing to do with “fast”. Speedrun commanders are fast. But other comments here are mostly right by my opinion. Strong for me is how many enemy forces can commander annihilate in endless engagement before dying. In that regard zagara is probably the weakest, other commanders are fine and don’t need to be compared cuz they are just good enough. But anyway the game is mostly early and mid and early lategame in co-op so Zagara is strong too. Zeratul is just overpowered and cannot be counted in total list of commanders cuz it just would be ridiculous. Funny to hear how Han&Horner or Stukov is weak, cuz Stukov is just not op and have slow forces, but can pretty easily decimate alot of strong enemy wave. Mass inf liberator vs air and mass tank + some bunkers vs ground and everything is melt without a chance to win. Horners just can attack they whole map’s ground objects without retaliation (ground waves basically non-existant for this commander) and this is concidered weak? I don’t think so. Horner has problems with air but hey - now we have zero-gas widow mines.
Some commanders has very strong ally buffs, but noone for some reason considers that. Like Swann with his “long” ramp-up time (ofc the fact that his ally will have shortened ramp-up time means nothing, its not co-op after all). To compare commanders in co-op mode only legit comparison is match pairs of commanders, and while some OP commanders would probably win in that test, it only proves that some commanders like zeratul or dehaka needs some nerfs, not their strength.
I mean, most mutations can be beaten by any commanders, it’s just some of com pairs would be alot harder to execute.
Another thing about weak and teamwork - some player consider Alarak weak cuz u know - i don’t know why really. Without ascendants he is pretty less powerful, but i guess ally has no problem to clean up structured after every opposition was smoked. On top of that, i recently tried to play some Alarak co-ops, and decided to blow my 2 gas when i have got enough ascendants and giving ally an opportunity to increase their production that way. Result is pretty impressive. My point is - co-op is co-op and solo measures is just off the discussion here, if someone is going to measure commanders strength, it should be measured is how well he does in pairs.
For me, when i face weekly mutations, the most common my answers to it - Kerrigan, Abathur, Vorazun, Swann. I don’t play zeratul and other after him.