I've never really been able to figure it out. Tell me if this situation makes any sense.
I have 3 players on my ML roster who can either play 1B or DH. Let's call them Tom, Ed and Bill.
When I go to set up my lineup VS lefties with no DH, the sim suggest that Bill play 1B and neither Tom or Ed is in the lineup.
When I do vs lefties with DH, Tom is playing 1B, Ed is DHing and Bill is not in the lineup at all. How does that make any sense? If Ed is the best player to play 1B with no DH in the lineup, shouldn't he be in the lineup with a DH as well? All 3 have 1B as their primary position.

Can't answer Wylie's question, but the actual players don't matter here. He's just asking how can a guy be the best option to play 1B with no DH, but with a DH he's not even considered one of the best 2 options,

But the actual players may matter. The situation seems so odd that one would have to see the players to try to guess what's happening.

The players do not matter because how SIMAI sets line-ups seems pretty random. I lost my 2B in Coop. I had no other primary 2B on the BL roster. I had 2 CF with 2B listed as a secondary position(as well as 2 SS). So I hit optimize to see what Simmy thought. The CF was put at 2B. The catch was that one CF was the 2B VL and the other CF was the 2B VR. Made no sense because both were in both line-ups but swapped positions on DEFENSE depending on opposing pitching.

Player Profile: Alfredo Serrano - Hardball Dynasty Baseball | WhatIfSports
Player Profile: Dee Hernandez - Hardball Dynasty Baseball | WhatIfSports

okay, I don't think the actual players matter, but here they are:
https://www.whatifsports.com/hbd/Pages/Popups/PlayerRatings.aspx?pid=5427179
https://www.whatifsports.com/hbd/Pages/Popups/PlayerRatings.aspx?pid=8129241
https://www.whatifsports.com/hbd/Pages/Popups/PlayerRatings.aspx?pid=6739457

and of course when I tried to see who simmy suggested played when today, it gave me different recommendations than it did yesterday