I played a very long Saba campaign using one of the pre-v.81 EB builds. My strategy was different from yours, partly perhaps from playing VH/VH, but also because it was all-Saba units, no placeholders.

I was very quickly at war with both AS and the Ptolemies, and that was so early in the game, it wasn't even feasible to think of Dumatha. Anyway, the most enjoyable part of the game was I decided not to use a Siege strategy, but rather to try and beat the Greeks in open battle with what is essentially a skirmisher army.

And it is possible, but VERY difficult. You need numbers and tactics. Any thought of going line vs. line against those tough phalanx forces is close to suicidal. After 100 turns I had to leave the campaign and move on to testing newer builds, but by then I had control of all South Arabia and was finally strong enough to think about moving north to Dumatha.

The one salvation of the "South Arabia First" strategy is you have advance warning of incoming invasion stacks from Egypt and Seleukia for MANY turns before they get to your heartlands. So you are never surprised and can make the stack adjustments necessary to increase your odds of victory.

A real fun faction to play! Not least because your unit mix forces you to learn a style of warfare that one would NEVER select if playing almost any other faction. Which, IMO, is one of the greatest strengths of EB.