By platoon I was referring to the concept that Hanley is going to replace Moreland at first everytime we face a LHP.
I get the min/max logic involved, I just question whether this all actually plays out like that in extended reality. Barring an injury to Moreland, I wouldn't be surprised if a mostly healthy Hanley's games played by position split ends up looking a lot like a complete flip from last season's (which was 133 at 1B/ 11 at DH). Interleague play and a few select games here and there..that's it. Which I'm guessing is notably less then the amount of times your scenario calls for a Moreland replacement.
Leaving a setting where Moreland is getting a lot more at bats against LHP under the current setup. Unless Young does indeed learn and put in some time at first. Even that is pretty questionable though imo. I see it more likely that we spend ST hearing Farrell praise Moreland's defense and intangible value as an everyday player.
I'm with you. We've seen how Farrell manages, including when he had Chris Young on the roster. He picks his starters. He does not sub people out based primarily on platoon advantages. So let's do it backwards:
OF - He'll play JBJ/Betts/10D, as his first line OF starters. He'll work Chris Young in there somewhat randomly, regardless of the handedness of the opposing SP, to keep Young fresh. Maybe Holt/Swihart now and then, also somewhat randomly, or to cover injury.
2B - Pedroia, and SS - Xander, are locked.
3B - Sandoval's to lose. But if so, Holt/Rutledge? Maybe Sandoval with Rutledge in a platoon role against LHP? This is the one platoon I can see Farrell formally adopting. Although it wouldn't surprise me if Sandoval was given a bunch of starts to "prove himself" against LHP before an official platoon was set up.
C - Leon/Swihart. Vazquez as needed? Farrell may "caddy" a catcher, but he won't routinely allow the handedness of the opposing pitching dictate who he plays.
I think the following dynamic dictates (or cements) what will happen in terms of subbing everywhere:
1B - Moreland. Was a starting MLB 1B last year for 130 games. Farrell will absolutely give him the spot. It will be Moreland's to lose. He'll be spelled (lightly, randomly) by Hanley/Holt. (Perhaps Hanley only for interleague games.)
DH - Hanley. He prefers to DH. Again, Farrell will just give him the DH spot and he'll get the lion's share of ABs there. I don't see Farrell subbing out Hanley much, since a) we don't have any sort of better PH bat off the bench, and b) there's not as great a need to PR for Hanley as there was with Ortiz.
Conversely, Hanley can only cover 1B, which he can do adequately. So, in reality, if Moreland was sucking, they could have Hanley play 1B, and use any better bat than Moreland's at DH. Granted, in reality, Swihart or Young may be the bats to outhit Moreland, regardless. But I don't see this happening unless there's a complete Moreland implosion. And even then they may trade for a 1B.