Edit: For command trait I figure staunch defender, artefact Staff of focus and mount trait Steel pinions. Arcanum general and got the artefacts. Maybe drop battlemage, exchange geminids for spellportal and add a unit of Prosecs or Libs. I think I'd rather have a second incantor than a battlemage though. Most of their unique stuff is featured in the realmspells.
Barely got any response on fb so I'm reposting this here. Let me know what you think!
"Looking at how I want to build my Stormcast list, I wanna play around with allies and have some shooting. Phoenix is lovely model, good unit, battlemage has some nifty extra abilities. Plan is to bubblewrap with sequitors, most things will probably wanna huddle close to that. Decimators dropped on a objective or close to blob unit, they're quite sacrifical but will be a pain to kill. Buff phoenix, spam spells, go to town. What do you reckon of this list, what would you do different?"