Zamasu had taken Vegeta's body?

[withheldforprivacy]

Assume that, for whatever reason, Zamasu decided to switch bodies with Vegeta instead of Goku.
Does that affect the plot?

 

[Captain Cadaver]

Vegeta's body is equal to Goku's at the time and in Super both are given equal recognition as fighting geniuses, so most likely nothing changes manga-wise.

Anime-wise, Vegeta's greater love for his family may give him a greater rage boost than Goku got, especially when considering his "MY BULMA!" scene, so maybe Vegeta would take care of Black himself before he has a chance to Potara fuse with Zamasu. Whether it be through his own power completely destroying Zamasu as Vegetto was implied to be capable of or them returning with the correct talisman due to Vegeta's lack of necessity to use the Rosat allowing him to double check Galu didn't make a mistake, Zamasu is likely dealt with without the need of the Zen-Oh button. That said, there's no 2nd Zen-Oh. Due to Goku not bringing a friend for Zen-Oh, however, Zen-Oh likely gets angry and erases Universe 7.

 

[Papasmurf]

Merged Zamasu ends up shorter and thereby has a greater rage hax when he turns his arm purple, allowing him to beat Vegetto

I'd go with CC's version of the events, or the sealed Zamasu just getting taken to Zeno to be his torture playmate until he gets sick of his NINGEN!! ramblings and Hakai's him and the entirety of U9.

 

[withheldforprivacy]

Vegeta's body is equal to Goku's at the time and in Super both are given equal recognition as fighting geniuses, so most likely nothing changes manga-wise.

Anime-wise, Vegeta's greater love for his family may give him a greater rage boost than Goku got, especially when considering his "MY BULMA!" scene, so maybe Vegeta would take care of Black himself before he has a chance to Potara fuse with Zamasu. Whether it be through his own power completely destroying Zamasu as Vegetto was implied to be capable of or them returning with the correct talisman due to Vegeta's lack of necessity to use the Rosat allowing him to double check Galu didn't make a mistake, Zamasu is likely dealt with without the need of the Zen-Oh button. That said, there's no 2nd Zen-Oh. Due to Goku not bringing a friend for Zen-Oh, however, Zen-Oh likely gets angry and erases Universe 7.

Goku would have just become a friend of Zeno's himself. Also, i think that, without that discussion the two Zenos had about how lame
some universes are, there is a chance he wouldn't have decided to erase the universes that lose the TOP, or Goku could've convinced
him not to if he had become his close friend instead of Alternate Zeno.
What about Alternate Trunks, before using the time machine? Would him having to face the body of his father have affected him
during the fights?

 

[Captain Cadaver]

Goku would have just become a friend of Zeno's himself. Also, i think that, without that discussion the two Zenos had about how lame
some universes are, there is a chance he wouldn't have decided to erase the universes that lose the TOP, or Goku could've convinced
him not to if he had become his close friend instead of Alternate Zeno.

Whilst that's possible, I still see the planned erasure as happening as I believe the Grand Priest would've had some influence in the matter.

What about Alternate Trunks, before using the time machine? Would him having to face the body of his father have affected him
during the fights?

If seeing the villain have the face of the man his mother spent years building a Time Machine to save and who Trunks treated as his one true hope prior to Gohan's transformation didn't affect him after coming to the realisation it wasn't actually Goku, I doubt seeing Vegeta Black would affect Trunks long term.