Obviously this is assuming Tyler will be back soon.
But between Tyler, Josh, and Roy, which one least deserves to be starting right now? You have to say Roy, right?
So why not let Tyler be your "let's try to score with a big" player, while Josh does everything Josh does best, and you also are a more mobile starting 5 with them sharing the front court.
Do I wish we could have Roy's game? Sure, when he brings it, but right now he's not doing that nearly consistently enough, so I think it's time to get the most out of Josh and Tyler. Both of them are 'bringing it' more regularly than Roy is, and I like what they bring as a pair as well as individually.
Let Roy come in a little later in the game to see if he can get it going against tired starters and their backups.
Look, this isn't how I want things to be. I want Roy to deserve to be our staring center, but for now I think it needs to be different.