I think its an isekai/ time travel genre. I can only one scene where 2 soldier/knights talking on how they would attack a place fortified by trenches and barbedwire which was a new concept to them 3w2w6d

Think there was a scene like that in one of the more recent chapters of Isekai Tensei Soudouki...

EDIT: After a quick look it seems like it it is the beginning of chapter 49.

~4400 manga completed
~1700 ongoing...

Thanks