The profile states for the Haradrim Warband, Raiders, and Serpent Riders "The entire formation may be given bows for +5 points per company." Do they have bows in addition to their current weapons?
Can they be modeled as a mixed company?
Specifically, like the Raiders and Riders both have lances. They don't lose their lances because it doesn't say replace, right?

Thanks.

Yes. If you buy bows, then they have both and you can model them mixed. Just like how they come in the boxed sets.