Concerning the doppelsoldner literally double pay soldiers (double handed swords men and halberdiers) consider them as as a sub unit. From what I have read they can be either front rank troops, a flanking unit, or the famous 'verloren hauf' or forlorn hope. There's no point in burying them in the ranks, they would lose their effectiveness, but out front, backed by the pikes in the subsequent ranks that is a different matter. Similarly if they can come in from the side they will do great execution.
I have read of doppelsoldner advancing down the field swinging their zweihander swords and halberds around their heads shouting "Hut - baur - ich - kom!" (forgive me if I have spelled anything wrong) literally " Watch out I come!". I'm guessing that these guys are at a really open order to avoid hacking themselves to bits.
You'll need a red flag wielding figure for the verloren hauf as it was traditional for them to have a red flag or Blood Flag (blutfahn?).