TFT champion finder

Ok i've played alot of auto chess maybe not TFT but dota auto chess underlords and the like. I know for a fact that if somone pick the same unit as you that unit is less likely to show up on your board to be selected. BUT as you collect more of them and upgrade them they should show up more. for example, if i have 2 2stars of a tier 1 unit and one 1 star of that same unit i should have a better chance at finding the last 2 i need and to counter that people should be selecting that unit as often as it shows up to counter my chances of finding it. BUT as it is now the way the system works is that as you level up tier 1 gets less common same with t2 and t3 which is stupid. The current way to play is to start with t1 or t2 but then later game just kill all two star units and get t4 and t5 units as they literally do the best. like getting liss with an ashe and voli and sej combo its broken the freeze lasts way too long and its easy to get this cause most of the time when you get to be able to get liss you already have at least one 3 star of one of those three.