Well, I think this is brilliant. And it further shows how unnecessary it was for Khan to be in STiD. Just a simple change to the expository backstory dialogue and Soran perfectly fits instead of Khan. Actually, it would even make more sense for Soran to be the bad guy. As a member of an advance alien race would be a much better choice to make advance weapons and ships than some 20th century despot frozen for 300 years.
Perfectly fits. Well fits as being intelligent and English.
* As The Stig has said Soran only cares about Soran and its really unlikely that Starfleet would hold Soran's biological family hostage. 20th century criminals maybe but not kids and a wife.
* In the 23rd century Soran is presumably some sort of happy guy.
* Other El Aurians are known to be hanging around Earth who might help Soran out
I agree he fits the same sort of arrogant personality though. I don't really care that much if the enemy's TNG or TOS but Soran fits no better than Khan