Don't think a bronze Bandit will do you all that much good.

If you have MANY Eunice's you could level one up and cost reduce him a couple of times so that he's your emergency low cost high HP damage sponge.

However, I would work on Imelia, That is assuming that she is the same cost (or lower) than your Lyla... They're generally comparable units, but Imelia has a bit better skill and her awakening gives her 10% more HP (as well as other bandits on your team). Did you manage to cost reduce / skill up her at all? Lyla is by no means a bad unit, but Imelia certainly replaced her in my roster...

Though again, I don't know how good a quality Imelia you managed to snag (mine is min-cost / max skill so it was a no brainer for me). Lyla is by no means a bad Bandit, very good offensive bandit for sure, but Imelia just outshines her that little bit due mostly to her skill and awakening passive.