Yes it is true that some drivers have more "luck" in hotlapping, but the gaps in the hotlap charts were way too big for that. 2.3 secs splitting division 1 first place and division 2 first place, so I dont think they can compensate it while racing. However there might be some drivers who just didnt have time or didn't bother to hotlap much.
Anyway I guess there isn't any better way to split the divisions than hotlapping. Although we could have a pre-race for splitting them, but that isnt 100% accurate on drivers real speed since there can be crashes ruining the result etc.
Now you are talking back to the division system and I dont agree with you. The reason divisions are made for making the races more competitive for everyone. For example if u have 50% of these fast racers and 50% of these slow racers in division 1, then theres no chance these slow racers can be with pure driving in TOP10 or so. Also one point is that generally these slow racers can be newbies without experience and cause lots of problems when racing against experienced racers.