think about distro like there is an in-game coach who is also looking at things like, how good the offense and defense are, who has good matchups at a given point in time, etc - and is adjusting distro on the fly accordingly.
i'm sure there's no actual in-game coach but there is a collection of actions taken within in the engine that one could reasonably think of as basically your in-game coach.
distro is probably one of the biggest areas that people are still unaware of the role the in-game adjustments play. that is the reason i will recommend folks to change lineups to match good scorers with bad defenders - but then to limit their distro adjustments, in 98% of cases, to just 1 or 2 (assuming a top player of about 12-14 and mid tier scorers in the 4-8 range). the reason for this is that you don't want to way overdo it - your in game coach (if you will) is going to call that guys number more when he is facing bad defense anyway. so by making a full adjustment yourself, the full adjustment you'd like to see, you'll basically overshoot.
anyway, what is probably happening is that your in game coach, who more or less is not the smartest tool in the shed, but at least is capable of dressing himself, is making an assessment for whatever reason, that your one particular guy is way better than all the rest and therefore, he is getting a lot more shots. you could override this by raising everyone elses distro or lowering his (lowering your best guy from 1 is not always the greatest idea though).
FYI, i would basically recommend not setting all players to 1 distro. i assume you are just doing that temporarily or something, but i figured it was worth a quick mention in case any newer coaches read this and thought that maybe setting everyone to 1 distro was a thing. some coaches will set everyone the same early just to see what the engine does and how things go, before setting real distro, which is fine and all, as long as its seen as an info-gathering tool and not an actual strategy for doing well. although to be honest one year i got so frustrated with distro, i set all my players to 0 for the final four and title game and won by 40 and 26 points (i had used 0 distro during the season at times when i was similarly frustrated, so it wasn't blind or anything, i legitimately thought my team was better without distro than what i was doing. i was a young coach then). so its not guaranteed to be awful - it can work ok when you have a balanced team offensively like i did - but you really want to try to do better.