I think the two big question for Kerensky was, could the SLDF have survived the first three claimants to First Lord via invasion of the Hegemony, and held off the next two challenges? And, prior to that, could he have kept the SLDF/THDF together?
I don't know on the first, but it's been argued it would have been a case of 'simply too many enemies' and the only question being who could hold off the longest. For the second...considering there were desertions to the Houses in small numbers, it was clear the SLDF wasn't going to stay around completely. When the Fed Suns got their hands on an entire Royal assault regiment wholesale, it was clear there was going to be much more, and that's when he said Nope.
Did he make the Succession Wars easier? Maybe. A lot of high-end tech and warships didn't get involved that could have. In retrospect to the scale of things, though, I think that's the equivalent of taking the third stage off a thermonuclear warhead. Sure, dropping 2 or 3 megatons from a 5 MT warhead is a big reduction in damage...but you're still talking a multimegaton bomb going off.
Idly, there's a thought - what if the SLN had, horrible pun intended, jumped ship to serve with the House fleets? Double those across the board and suddenly the 1st SW's naval battles and bombardment tactics might leave us with a planetary headcount equal to the Inner Sphere from the first Mechwarrior RPG...