Last year the Sox scored 100 more runs than the second best offense in the AL, so, even without Ortiz, I expect the Sox to do better than "top 3-4 offense."
For counting purposes, I assume Moreland, not Ramirez, is Ortiz's replacement in the lineup. That's a pretty big drop-off. Sports Illustrated used to have a stat called "runs produced." It was runs scored + rbi's - home runs. Last year Ortiz "produced" 168 runs for the Sox and Moreland 88 for the Rangers. Even if they can't make up for those 80 runs between 168 and 88, the Sox would still have the best offense in the AL--maybe. I think the Guardians, who were second in scoring in 2016, picked up Encarcion.
On the other hand, I expect Sandoval and Benintendi to be pretty good plus-ups. Pedroia might go down a little, but Bogaerts should go up. I will be more than happy if Betts and Bradley are about the same as in 2016 even though both are young and could improve. Leon will still be Leon, but Vazquez should be better than he was last year at the plate. Ramirez 2017 should be on a par with Ramirez 2016.