Assuming we don't get anyone else, I think McCoy will be the LT. Buchanan the RG. Merriweather will be the 6th OL. I wouldn't be surprised to see SJ as the starting C if he can gain some good weight.
Samson pulling in gap scheme runs is a thing of beauty. Unless he's far superior to McCoy pass blocking at LT, I'd rather he stay at Guard, since we pull our guards more often than we pull our tackles.
Mirabel replaced all five OL starters for the COVID year at Oregon. They gave up 11 sacks in 7 games, and Dye ran the ball well (Verdell did too the first few games till he got hurt IIRC).
Cantwell being ready to start is a big key. If both McCoy and Samson have to play tackle that probably makes Merriweather a starter at one of the guard spots. That would be our weakest line, IMO.
Wildcard would be if Mirabel likes Wilkerson/Campbell enough to start one of them at tackle. I know he spoke highly of all the freshman OL during a playoff presser. Could just be coach speak. Doubt he starts a true and redshirt freshman at both tackle spots, but it's a possibility to consider.
Kinsler coming back I'd be down with, but he'd have to beat out Buchanan to start on the line. Everytime he came in at OT in garbage time I always thought he was playing out of position, had cement feet, and would never be a starting OT here.