The full-blown rally version of Trump is the opposite of subtle, but it would take a decent actor to play the other versions of Trump. Like standing at a podium, bored and drugged up, reading a speech he’d rather not be giving. Or the version of Trump in the WH residence every morning, watching Fox TV, gloating and planning his Twitter posts of the day.
More than anything else, it would take a good actor to play someone who is truly stupid and incurious, with a diminishing mental capacity due to age, and yet holding the levers of great power. The rally performance of throwing red meat to the base would be the easy part.