538 did a thing on the power centers/factions in the Trump admin. about three weeks ago. Not sure if the bureaucrats count as a faction, but point is, there are many power centers and Trump apparently fosters cutthroat competition between the factions. And he loves it.
In terms of apparent influence, I'd rank them:
1. Trump Family (nepotist to the end, made at least one direct policy change based on a suggestion from Ivanka, incest is truly a force to be feared)
2. Wall Street (AHCA written by insurance executives, tax corruption policy focus, not sure how NAFTA interacts with these people)
3. Bannon (travel ban attempts, anti-China, getting some vibes from the SCOTUS nominee)
4. McCain (hates McCain himself but Trump goes out of his way to suck off the military, was insistent on McMaster, also Mattis but he and McMaster both seem to be outside the Trumpsphere
TM and I foresee there being Problems if Trump starts insisting on a God-Sorting military strategy to either.)
5. Pence (what ever happened to the First Amendment Defense Act, again? Oh, committee hell. Trump seems to avoid even pretending to care about the religious right.)
6. Party People (impending night of the long knives, believe it, also who the fuck eats cinnamon gum Trump is right on this one)
7. Bureaucrats (Trump is openly hostile to them and some of them are engaged in active subversion against the administration)