You could build the second castle right at the start, giving you more gold early. Also, the technodromes also work for wood storage, so place them next to trees, and have workers harvest there, too, so they have shorter ways and can thus harvest quicker. When catapults are loosing HP place them in the second front row (remove them from the first row) so they can still attack while they don't break instantly.
The reason this works on this map with this faction pairing is because of the single narrow path, and because you're making use of one of Tech's unique strengths and one of Romans unique weaknesses (when played by CPU). A human (Roman) player could take you out with a mix of fire archers, catapults (probably rather ater in the game) and spearmen (serving just as targets for your catapults, keeping the fire off the fire archers and catapults).
