Siege

[Enforcer]

This is DOS real-time strategy developed and published in 1992 by Mindcraft Software.

[Saccade]

Moby link (http://www.mobygames.com/game/dos/siege)

I remember this series, but not this game - they ruled! as far as I can make out the remnants of a distant childhood, through the haze of an old man's mind.
Bloodstone was especially awesome. Because it's the only one I can really remember playing.

None are as good as Reloaded's (http://www.reloaded.org) Dark Disciples, tho.

Siege looks like Dune II: Battle for Arrakis a bit. (that's probably the only resemblance).
http://www.mobygames.com/images/shots/thumbnail/1075059149-00.jpg