The problem is that Bannon’s style causes the opposition to build up, organize and fight, thus you always have heavy casualties and often lose.
Trump causes his enemy to underestimate him, think he is bumbling, and the Trump comes on strong strategically and wins.
The Republicans worst nightmare would have been for loose cannon Bannon, (new name for Trump to use), to get a conservative to run as an independent and siphon votes from Trump in 2020.