Moose himself says they're pretty basic "generally pretty good" build orders, rather than necessarily being totally optimised expert options. This is probably extra true since this vid came out before the latest patch.
How does this retold version differ than the AoM game thats still active on Steam? From everything I've seen, it just looks like a graphics upgrade.
So today there are two versions on Steam. The "Extended Edition" which came out in 2014, and "Retold" which came out two weeks ago.
EE was basically just the same as the original CD version from 2002, except altered to support modern screen resolutions, and then they added some new balance patches and a Chinese civ which were extremely poorly received for a whole bunch of reasons.
Retold looks much, much better with proper newly-crafted models and textures. It took out the worst of the patches from EE and the Chinese (with a promise that the first expansion will be an "all-new" Chinese civ). It's also got a heap of design changes which have mostly been regarded as positive: god powers are reusable for a Favor cost (with Atlanteans balanced by their Favor cost to reuse being much lower than other civs), the house limit is raised so you can build bigger armies, and the UX is enhanced with better hotkey support, among other things. It also has good multiplayer servers, rather than being peer-to-peer, so lag is vastly reduced.
