I realize that this s a tad late to the conversation, but I figured if I could contribute something pertinent then why not. Anyway, as to the issue of mods, there are games that can support mods, but support for this needs to be programmed into the game. For instance, the game “Pike and Shot” or “Battle Academy” both have had scenario building support. You need the Windows version to build the scenario, that cannot be done on the iPad, but then you can make the files available for iPad users to DL.
As an aside, both games are no longer compatible with the current iOS. They’re both 32-bit games and have now fallen by the wayside when Apple, in their infinite wisdom, chose to screw over millions of their customers by rendering large portions of their purchased software obsolete. But I’m not bitter.....
Anyway, my point being that you can still find these games if you have an older iPad with 32-bit support, but otherwise they don’t appear in the App Store. Unfortunately, Matrix Games and their associates have no plans to recode their 32-bit games to 64-bits..... and I can understand why.
Don’t know if this info. is useful, but I wanted to put it out there. Best wishes!