Ok this is weird.
When training heroes - if you are full on hams (storage full) - and you ‘undo’ training that clearly hasn’t started yet (the waiting line) , the game gives you a warning you’ll lose resources. Duh, hams can’t be stored again. BUT: you’ll lose your recruits too! Even if there’s more than enough space to house them.
Same goes for crafting items. If the hams can’t be refunded, your ingredients are gone too.
If the hams can be refunded. You’ll get everything else too.
I was shifting tc13 around and it cost me 70 recruits. / tried it on some minor potion too, just to see what would happen.
All or nothing… seems weird.