Thanks for the detailed replies. I am relieved to hear that money is not going to be a problem later.
N3MES1S, you are right about royal snakes. They are very good and form my first line of defense. (The only complain I have is why they don't have 9 heads

) I used marauders to replace guardsmen because I want to avoid casualty. I hesitated when I made the decision since I was not sure whether it's worth the cost. But it proved to be a good investment and I am going to keep marauders in the army for a longer time.
And thanks for the comments about HOMM V. I will stick with armored princess then. I am just missing 3DO and Strategic Simulations Inc.
p.s. For members here never try marauder's search ability. Here's some information. After one typical battle in Debir, the prize was about 150 golds, two chests dig offered about 100~500 golds or some scroll, and marauders found about 600~700 golds. (Sorry I can't be more accurate because I have the game at home.)