I’ve tried nubby a half dozen times, and even with aggressive healing and the tactic you suggested, there is enough chaos that the dollars invested probably pans out less than 50% of the time. Kobold, that guy with Silence, and the Knight pretty heavily punish low HP and right-side universe situations and it is pretty common to get one of them, so you have to keep investing on healing. I’ll buy a nubby before a final fight if I think I can roll over boss (e.g. I’ve got EMP and some other shield game vs. Princess), but I’d rather reroll most days.
Maybe the balance with sword and shield is to only add shield if you don’t have more than one or two.