You want to get nobles relatively early so you can get influence coming in to snag them. The biggest tip I have is to stack entrepreneur mages in your richest provinces. If you don’t take advantage of mages you likely won’t be able to afford more than two high tier armies by the time a short campaign in ME ends. High Elf economy has changed to be more focused on stacking embassies where you can and trading.
Edit: I have made some edits to this comment after completing my High Elf campaign with Eltharion.