If the B-suit manages to run before he dies, thats too fucking bad for you. You're the one who should've stopped him from running away, your the one who should've came up with a strategy to stop him, but did you? No, and don't whine that why would anyone think of such a strategy, because players who takes 1 extra step ahead of thier game are the ones who tends to earn the more kills.
Besides, can't this system be abused? Like, for example, I try to dretch a human and got 99 of his HP so I get 1 evo. He comes back fully healed with his Medkit and I dretch again, making him lose about 99 more of his HP. He runs away safely, but I got 2 evos without even killing him, so wtf? Also, it would make it possible for everyone to be i s3, wit full armour and class, but without getting 1 kill. You can think of ways to stop this, maybe you get an evo for doing 75% of his health. Wait, that means I basically got a free evo and if I lower the percentage, I might as well kill him. If I raise the percentage, I would get free evos more easily.
By the way, how did you get to be a dretch in S3? Maybe you got in the game too late, maybe, but then you could always go to another server. There isn't only one server in Tremulous you know. But maybe you fed too much and got the humans pwning your butt, so its your fault for over-powering the humans. And its also your fault if you can't seem to rack up enough evos in S3, I got dretched plenty of times as a B-suit in S3 by good players because they worked as a team, unlike what you probably did.
I don't see the benifet or intelligence of this idea in this topic, hell, it sounds more like a feature that the [X] Server would use. It sounds more like a player whining about sucking in Tremulous, so I agree with Player1, th eproblem is your skill, not Tremulous. Learn how to play better, practice more, spec the players better then yourself and don't think of ideas like these.