First,when u buy player which u will train on inside skills,look to find 1 with good secundary skills.That makes a big difference,in performance and in price,later when u would sell him...At least to have descent JS,HA and PA...
Also,check his potencial before u buy him,i wont go below than all star...
IMO u have better team than Indiana,especially when i saw that Indiana trains 28yrs old players lol...
If i were u,i would sell all 3 trainers and get 3 18yrs old with all star+ potencial and good secundary skills.For that purpose i would check other team in leagues,check if i can get play off having 1 18yrs old kid in starting line up,playing 48mins.If u can,then do it,before play off sell 1 of them and get outside player/s.In that way u would save money also in salaries,coz 18yrs dont spending much...