Actually he does need their support, at least mostly. And he will get it, mostly. Of course some dead enders will seek to undermine him, but for the most part they will play ball with Trump because otherwise they are out of the game.
I’m not really seeing how Trump needs GOP-e support. (Granted, he does need the GOP-e to stay out of his way and to not give money/votes to Hitlery, but that’s more of a neutral position.) He doesn’t need their money, he’s perfectly competent at getting out his message through the media without their help, and he knows plenty of competent policy makers who have never been under the influence of the GOP-e.