I think Perry could be more successful with better structure, but Kevin Lee can be grandfathered in the LW Top 10 rankings as he is. Why?
Kevin Lee is a good wrestler, and since MMA is pretty much wrestling with optional striking, Kevin Lee already suits the identity of a prototypical MMA fighter. A wrestler who can barely strike. Kevin Lee got rocked in almost every fight I saw him in (to be fair, I have only seen 3 of his most recent fights). Based on this weak evidence, he still looks like a "prone to get KO'd" fighter.
Mike Perry is hard to put away, and he can end the fight from round 1 to round 3. He is more dangerous than a Kevin Lee type of fighter. A fighter like Kevin Lee should beat you on points (if you are really good). However, with a fighter like Mike Perry, you have to stick to a game at all times, or you could get KO'd.
In my opinion, if Mike Perry gets polished i.e. learns to control his aggression, gameplans his aggression, learns better shot selections and etc, he would be a more dangerous fighter than Kevin Lee.
However, this means that Mike Perry has a lot more work to do than Kevin Lee, in order to compete at the highest level of the 170 division. This is not easy to do. So, realistically, Kevin Lee will probably enjoy a more successful fighting record, unless something goes horribly wrong for him.
Conclusion, Mike Perry can be a better fighter than Kevin Lee, but this will require a lot more work, which I doubt he is capable of doing. So, in the real, I will be surprised if Mike Perry has a better MMA record than Kevin Lee, when it is all said and done.
This is purely speculative opinion based on very little and weak evidence. The truth can only be known after it happens.