Wildlands graphics, controls, and gameplay with the workings of Jagged Alliance would be perfect in my opinion.
A mod could do this... if mods can be made for this game. Imagine these changes...
1. Merc teammates would be hired through a Agency, the more you pay the better the merc. Mercs have specialties.. heavy weapons, spotter, sniper, etc.
2. Make money mean something. Collecting money from drug lords, robbing from the cartel, getting paid to do missions, picking up bounty missions, doing jobs for the rebels. This money could then be used to pay for weapons, gear, vehicles, information, and ammo types like hollow point, armor piercing. This would add so much. You would want each shot to matter... because you are paying for it.
3. Returning to already completed areas to either fight cartel or Unidad when they try to move back in. This would offer replay opportunities.
4. Investing in local areas by paying for rebel support or arming rebels... thus making it so you do not have to return to an area if you do not want to.
Those are just a few ideas. Finding accessories on a mountain or in a small building is odd to me. Picking up a weapon off a enemy and not being able to keep it, yet if I loot from a crate I can keep it, does not make sense to me. Gear should matter, armor should increase bullet resistance, camo types should matter.
Ubisoft could take quite a few notes from Jagged Alliance 2 in terms of gameplay, that's for sure. The original hasn't dated as well.
It's a shame that most of the younger players (and those not on PC) probably wouldn't have even heard of it. They missed one of the best tactical combat games of all time. It's a game that I still dust off every few years to play again. The fact that the JA community is still around too speaks volumes.
Another thing I'd like to see in Wildlands from JA is that the rebels slowly take control of the bases left behind after you complete a mission there. It would add to the feeling that you're actually making a difference. At the moment the Narcs just come back so it feels like you've done nothing really.