I would do it so if there’s a difference of 3 between the team scores, change the leader over. I dunno how your system works, but it’s definitely working. But anyways, I’d do it like this:
if (CT team score) – (T team score) >2
(change over player with most kills on CT to T)
vice versa
I’m still skeptical as to whether or not a KD system would work. There can easily be a 30:3 guy and a 6:0 guy on the same team. If you wanted, you could have it look at the top 3 and compare their KD’s. Then move the best one over.