It’s quite easy to screw up perk selection and removing wrongly selected perks is very expensive.
Please add an undo button that gives the possibility to go back with our selections up to where we started off when opened the perk screen, without extra costs, regaining all points spent. Once we leave the perk screen for the given soldier, this undo option is lost, the soldier is trained as we instructed.
For casual players it’s not always straightforward which perk costs just too much, so the optimal combination for the given soldier may need a few attempts.