Honestly imo Trots and ultras can feel very similar and they can come off as virtually identical.

I think there's some key differences in how they approach things and how they go about what they do, but if you put me in a room with 5 trots and 5 ultras it would take me a while to figure out which was which.

It's a lot like syndicalism vs council communism or Titoism vs market socialism or [CW for a hot take] platformism vs vanguardism/Bolshevism; maybe the road is slightly different or (lol) the ideological window-dressing is distinct but you end up at essentially the same place regardless. How much emphasis you want to put on the ideological currents behind these movements compared to assessing their impact and outcome, and how exactly you want to attribute things to either being ideologically-driven or a product of material conditions, is a personal matter imo.