I believe Dawn of Fantasy will differ quite a bit from other RTS titles in terms of creating strategies. There is so much involved in DoF to make it more realisitic that strategies like turtling and rushing (not quite sure what booming is) will become quite obsolete and players will have to develop more realistic strategies.
No comander in their right mind would send in a small untrained force at the start of a battle, with a 50/50 chance of winning or losing. Just as no one would rightly stay in their fortress waiting for their enemy to just give up.
Features like our line of sight system, layered maps, complex combat and powerful magic I think will add counter-strategies to pretty much anything. Allowing players of true tactic skill to win, over people who employ cowardly strategies, or attempt to just annoy their opponent.
For example, if someone is turtling in their fortress, take your mage, and send a huge volley of fireballs over them, no one is going to stay in a place covered in fire while your units burn to death. Dragons who stay in their caves are going to be at a disadvantage not being able to fly, or breathe fire without collateral damage will be devastating to them when legions of pikemen come in and skewer them.
To ward off rushers, place some scouts on high points to be able to get a good line of sight, anyone coming with their small army to rush you will be sorry they did because you knew they were coming.