I have absolutely no doubt that Tonda Eckert knows Ross Stewart is a far better striker than Cameron Archer. No doubt at all. The fact that he started the latter should tell you something, i.e. he didn't want to but on the basis of fitness he was left with little choice. I'm sure the idea of half each for Larin and Ross also occurred to Tonda, so again, if he didn't there's probably a pretty good reason for it.
I don't think Tonda quite envisaged the game as it planned out but saving your stronger player for the second half, isn't the stupidest idea ever.