Originally Posted by HoreTore
Can't really see why you want levy spearmen when you have stakes? Set up a nice front of stakes, and place the bills behind. The stakes will kill the cavalry dumb enough to charge and the bills will absolutely destroy any infantry. Place your own cavalry at the flanks to take care of any cav trying to flank you and avoid the stakes.
If you assault a city with a lot of cavalry in it, you'll probably want some spears though, but merc spearmen can do the job well enough.
Just remember that bills are a CHARGE unit, and not hold unit, and they'll do good.