In my experience I have found better trading occurs when I run the top branch and trade for the techs leading to MT. There are more optional techs to sidetrack the AI so that we can get a monopoly or two on our way up the ladder. If we are a step behind on the MT branch, we could end up being second fiddle the entire way. However, with Greece as our next door neighbor, those Hoplites+walls are going to a major pain even for knights. It would be nice to have some Cav & cannons to bust them up. I'm at work and I can't load the save at this point, but if we still have a lot of land to cover it might work to go the top branch. If the world is shrinking around us, then MT. Maybe I missed this in the notes - but is Engineering still unknown? If we need to research Engineering ourselves, that might also be a good reason to go towards Theo; Theo may have better trade value later, assuming we are not the first to either tech.