Any mods that make this game play more like predecessors?

[jman0war]

Compared to predecessors this game play is weighted heavily toward soft/passive strategies like Encirclement, ZOC, Supply.
The constant Retreating by enemy units also make the game less impactful and a more dull game play experience, just my opinion m'kay?

Anyone know of any mods that change rules to make it more like Panzer General or PG2?

[R2G2]

The Rules.json file can be easily changed to achieve what you're looking for. For instance, you could nerf the encirclement penalties and increase the percent of causalities required for a retreat.

The Rules.json file is broken in regards of the Mod Manager, so the answer to your question is no. This is a similar problem with other types of game files. It's been like this since the release of the Mod Manager, and a big reason why there are so few mods. The only option would be to alter your own game files. Just make sure you save a copy of the original.