One of my favorite strategy with Saba is to send a diplomat to Carthage. The earliest possible the better. Then burn my way across Egipt and if there are towns I feel I can't keep, I just exterminate them and hand them over to Carthage + some money gift to allow them to garrison it. This has two consequences: it might trigger a war Egipt - Carthage and release the pressure on you and if Carthage gets to keep them then they'll do all the job for you. They'll convert the town to the semitic culture you share with them and build it up. You can get it back later.