Are you still searching for a tactical ancient Rome era game?
Even tho it's pretty dated, the Total War:Rome game (and its add-on "Barbarian Invasion") is the only game to date that's 1) using historical tactics and b) doing pretty well in the gfx department (considering the original release date). Once you have figured the weaknesses and flaws of friendly and enemy AI it gets easier, but it's still a good challenge if you are pitted against superior (in number and quality) forces.
The 3D-part is a nicely set up tactical game, where you control up to 10 (?, can't remember) units, ranging from archers, heavily armed legionnaires, ballistas (mechanical "guns", shooting arrows) and catapults, light and heavy (armored horses) cavalry, warhounds to war elephants. You can also use chariots that are armed with fast firing mini-ballistas in the expanstion, IIRC.
The 2D-part is somewhat like Civilization, where you control taxes, recruitment, economic development and building of defensive measures like city walls, armed towers and reinforced gates (which come into play in the 3D battles). Prior to the battle, you can build siege towers and catapults, or you can order your force to dig tunnels under the enemy city's walls, so that sections of the wall come down.
The game costs around 5-10 bucks, I guess. I got the main game and the expansion for like 12 bucks at direct2drive a few years ago (when they used to sell stuff without online copy-protection steam-like crap).
It plays like a mix of Civ IV and say an RTS, as the 3D-part is pausable real-time (you can even up the game speed, to skip long chases, if you want to wipe out all enemies) but the 3D mechanics are not anywhere near the ones that can be found in RTS games, they are more realistic. A good part is based on parameter calculation (like in CO 2, say fatigue level, experience, leadership, etc), and one or another dice roll can be found, too (especially if it comes to the routing of units). It's a lot of fun, and in my books better than the rather dry approach of games like Civ (where you can't fight tactical battles).