I actually don't think the way the WAR breaks down matters much. At the end of the day the Cubs spending is inefficient. We're not getting enough WAR per million spent. The team needs more surplus or needs to spend more if they're ever going to be a 90+ win team. Players like Baez, Bryant, Russell, Hendricks, Schwarber, Contreras, Rizzo etc gave us a ton of surplus and we're nowhere close to that yet.
We may have almost twice the payroll as the Brewers but if we spend 3-4x on players of the same WAR it's moot.
If players like Caissie, Alcantara, Shaw, Horton, Brown etc can perform well we can afford to trade more expensive guys like Happ, Bellinger, Nico or Swanson, etc and sign upgrades elsewhere while reloading our farm to reload the surplus years down the road. Rinse and repeat.
The other option would be to trade some of those prospects mentioned for mlb-ready prospects at positions we need, like we did with Busch. I don't think trading 3 top prospects for 1 very good mlb player with 3 years left until FA and entering arbitration years is going to be enough. Maybe to get us into the playoffs but we should aim higher