Assuming it's a haven, as it appears to be, take a look at haven upgrades. I would expect walls and maybe even a bunch of improvements. About 30k haven def. bonus would mean 4x stronger Bonnie and that's without any other improvements.

Note that 1 dead Dagger means that the Bonnie killed between 0.5 and 1.5 Daggs (it gets rounded), so the bonuses only have to get her between 70 and 209 (to kill one Dagg with 140 off), and you can achieve that with just heavy haven improvements (no other upgrades/items/relics/... are needed), which means that - combining with everything else - even a decent haven improvements would do.

I'm pretty sure that with fully maxed upgrades and all, one Bonnie could achieve killing 2 of your Daggs or even 3 if they were at their default off of 100.

Because it was Crowbar's bonnie   ropl

(Not sure if it applies to this case but sometimes overkill on your offensive unit numbers creates losses too!)

Keel D. Haul said:

(Not sure if it applies to this case but sometimes overkill on your offensive unit numbers creates losses too!)

50 Daggers is not overkill. It's just a bit more than is needed for a decent raid.