While you are correct that there is little on Kolar, I feel that there is enough to make a well-reasoned debate for his side.
We'll see. I didn't expect this one to be as long as the others (most likely due to the lack of info on Kolar), but we shall see what happens. Maybe some will come to Kolar's defense. Then we can have ourselves a true battle.
Actually upon further review of Kolar I dont believe he was an Ataru master. He seemed to use some telekentics in his combat employing it with out warning and while this would normally suggest Niman we know niman users didnt survive geonosis if they were on it. So the most likely form to do this besides Niman would be Shii-cho. This however is not enough to conclude that it is Shii-cho the most valuable evidence comes in his ability to disarm his opponents. Kolar was sent for Vos because he was most likely to take the guy alive even if he were to beat him. And in many more fights with people it was likely that he wouldnt kill and sometimes he could even disarm his opponent with out injuring them at all. A users form normally reflects the user and while he was aggressive he seemed to dislike killing his opponent and would avoid doing so where ever possible. These are much more the tenets of a shii-cho user more so than any other form of saber combat.
Thus I would give the saber advantage to no one as they both seemingly used the same style and would have a similar skill lvl with said form. Instead we have to look at the likeliness and effectiveness of the use of force powers and other martial skill in combat along with physical capabilities which again I actually would give to Kolar here his resistance to pain means he should be much harder to disarm and his ability to throw in kicks and force pushes with out warning to his already mastery Shii-cho form could give him a distinct edge over Kit Fisto. So actually Agen might just pull this one off.