It might be helpful to consider how Diku combat evolved.
The concept of an attack in DikuMUD was based on the old D&D model, simplified. The coders didn't think in terms of players vs. a DM, and so every attack was designed to happen instantly, and then a certain amount of cooldown time got applied to prevent attacks from happening as fast the user could type.
By default, each round of combat, everyone involved in the fight got one auto-attack. Every other action takes place outside the normal combat rounds! If you want to see that, just change the combat tick from 20 to 200 (or whatever it is for smaug). Every round, you will take a swing, and the mob you're fighting will take a swing.
If you cast a spell or use an ability, you incur a WAIT_STATE that tells the interpreter to skip your command buffer and decrement your wait timer by one. When enough ticks go by, the next command is processed.
Some command have no wait state.... flee, for example, is applied immediately.
However, the point I'm making here is that EVERY attack happens instantly, and then you have X number of ticks where you do nothing.
If you contrast that with, for example, combat in an LPMUD, you'll see things like "Bozo begins muttering under his breath", and "Bozo waves his arms and trails of fire begin forming in the air around him", and "Bozo throws his arms forward and a ball of fire sails through the air at you!". In that system, the actual attack happens at the END of the delay sequence, not at the beginning.
That, in turn, means the potential victim has the chance to see what's happening and counter it. Perhaps they'll dodge, perhaps they can cast a sheild spell that takes less time to cast than the fireball spell does. Perhaps they can do a shield bash and interrupt the spell before it hits.
THAT is the key to making combat interesting. It doesn't need to be turn based, but it does need to be reactive. You have to have a chance to see what's about to happen and counter it.
In order to change the way combat works though, you'd have to first unthread how it CURRENTLY works. That's the hornet nest Kylotan is currently poking with a stick. *grin*