Having played a bit of all the Geneforge games and having completed 2(G4,G5) and almost completed G1, i feel like the in the rebel ending of G4 the PC plays a pretty useless part. I didnt help in the formation of the unbound, i didnt really keep the shapers at bay before the unbound were made, infact, I didnt even know about the unbound till they were almost ready. The only thing the PC does is a little battle test of the 3 unbound prototypes, which the drakons could have done, but this was simply more fun for them.
I feel that apart from Monarch, the infiltrators, and finding the shapers in the warrens, my poor servile was pretty ineffective as far as the war effort is concerned. Especially considering the final fight was just an all out slugfest. Not to mention, Monarch could have done nothing to stop the unbound, and the infiltrators probable would never have gotten past the Grayghost Gate (the tunnel into Khima from the windswept farm could doesnt seem large enough for a real force to enter), so the unbound were still pretty safe.
My general impression of the PC in most of the Geneforge games was of a single person who was in the right place at the right time and did something far more important than just kill things. This ending just seems in so different a direction from all the Spiderweb games i've played.