Civ Strategy Guides

I know there are plenty of build orders for Civs, but are there any indepth strategy guides explaining why you should choose that strategy and what makes the Civ good at it, aswell as more general stuff like "Celts faster wood gathering allows them to build a second TC in Castle Age while still having enough Wood for two Siege Workshops constantly producing units..."

Especially with Civs that don't have clear boni towards a single build its hard for me to wrap my head around what options I have and why this Civ is better at it than another.