I like to upgrade my troops with exact amount of XP needed for next level and nothing more. For example if I need 160XP and have 2x2* troops I won’t use them because it would give me 180XP - I would wait and use 4x1* troops instead.
Some time ago I noticed that for some reason one of my 4* troops got an odd number of XP, ending at 5 instead of 0. I was not sure how it happened as all troops give the amount of XP ending at 0 when used (40 for 1*, 90 for 2*, 200 for 3* and 400 for 4*). I know most people would probably ignore it or even never notice it but after I saw it once it started driving me crazy all the way to the point when I decided to actually sacrifice that troop using them to train another one just because I did not want to be stuck with that 5 forever… and when I was just about to do it I discovered I can get other XP values using trained troops - i.e. 1* troop at level 1 gives 40, but 1* troop at level 2 gives 48… So I started to train my 1* and 2* troops before feeding them to that 4* hoping I would get rid of that 5. But after reaching I few levels I discovered it would never work, as both 1*'s and 2*'s they seem to just gain 8 with each level, never reaching odd values anyway.
I did not try using levelled 3*'s, but before I do it - does anyone know what I should do to get rid of these odd numbers and be back at 10? I am happy to sacrifice more troops if needed but it would be better to know where I am heading rather than continue trying to feed random troops hoping they will become odd at some point.