When leveling up my companions I wonder how much influence their skill values have.
Personal skill seems clear enough that it only concerns the actual companion. Yet Party skills have me confused.
For instance, when building advancement or besieging a castle only the companion with the highest Engineer skill counts. So it seems ill-advised to waste points for other companion here. Same seems to be the case for Trade.
But is it also the case with e.g. Trainer, Wound Treatment, Surgery, and First Aid?
Will those benefits add up, as in will two companions with high a Trainer skill teach recruits faster, or does again only the one with the highest value count?