As someone already said in BB the only real limit is your imagination for tactics, almost anything works if you can play it out.
^ Pretty much this.
I had a playthrough that absolutely decimated in which I used 0 shields, but it was very much a brute force band: several two-handed-weapons guys, two Weapon Masters with nimble builds to tie up orcs / similarly tough enemies, a horn blower, a few crossbowmen, and a Confident stick with a crossbow. It worked pretty well, though I eventually tried it with two horn blowers and found that to be satisfying. Point being: even though the shield wall is the go-to tool to have, there are lots of other ways to fight enemies.
I’m personally a fan of two handed weapons. I always start my brothers out using shields, but slowly transition toward carrying pikes, two-handed swords, orcish axes and warbrands. The only weaknesses with such a setup are fighting folks with crossbows or fighting goblins. Outlaws are generally too weak to be a threat and orcs are pretty much mincemeat once pressed with enough two-handed weapons. I might keep a couple guys with spears around to contend with leaping orcs.