If, big IF, Rangers were in English Championship they should be able to compete. Rangers average player salary is about 30% higher than most clubs but only 2/3 of Burnley.
Every year the clubs relegated from EPL are the ones in contention for going straight back up. Therefore Rangers should be contending for the play off positions. Checking tables today there are 10 clubs within 6 points of a playoff position, or, to put it another way, a total of 16 clubs vying for promotion.
To think that Rangers would stroll into EPL is delusional. While Rangers might be able to compete salary wise initially, without the money from Europe would they still be able to afford a higher salary?
And would supporters be prepared for a string of defeats?
IMHO Rangers would be better off in Scotland trying to drag other clubs, kicking & screaming, into a more professional, and commercial, set-up