You are completely ignoring the Christian nationalists in this analysis. Just because some parts of Trump's political coalition are in it for the corruption doesn't make Trump less of a fascist. In fact the same was true of Hitler - there were powerful aristocrats that thought they could ride him back into power and it just didn't work out for them.
Fascists work by creating cult led reality bubbles and nationalism doesn't have to be expansionist. If Trump weren't 50 years older than Hitler was at the start of WWII, we would be in big trouble.
"Calling Trump a fascist is surrendering the fight to him by not engaging with what he is." - that's just nonsensical. Corruption will simply never be as dangerous as cult led reality bubbles. A charismatic leader whose followers care more for hurting perceived enemies than their own well being is more dangerous than a simple deal maker. We call Trump fascist because that's the more dangerous side of his politics.