I don't think Ford was planning on selling 100-150K Rangers in the US Market-everyone else outside of the Tacoma is under the 100K mark per name plate.
Adding a Lincoln to mix wouldn't strain the plant, because that would be lucky to hit 20K units a year and it would have to give up the removable hardtop on that the Bronco has because it never be able to get close to being a Lincoln in its current form with all of its NVH issues.
If they tried, they would need to throttle back Bronco production. It's a high class problem but you reap what you sow... and Ford didn't do enough planting.
Chicken Tax restricts Ford's ability to import Ranger from China or Thailand. The Michigan plant can only build so many T6... so Ford is leaving money on the table.
Not just Ranger but think about all the money Ford is not making on a Lincoln T6 SUV or Everest.
This basically sums up my position and is my biggest concern. I know other manufacturers have vehicles that are basically in the same segment, but it seems unnecessary to me in the truck market. I suppose if they use shared engineering, can be built on the same line and it really doesn’t matter which one sells between the two, it would be a moot point.