If the reserve guarantees were higher than the lower built lines, then they would go more senior (in theory) than a junior lineholder. This makes previous junior reserve guys happy since now they are junior lineholders instead of commuting to reserve.

Previous junior lineholders now get a higher value paycheck in exchange for being on reserve, or if reserve goes even higher than junior lineholder, than previous junior lineholder becomes mid level lineholder.

The only people that I could see that wouldn’t benefit from this are the most senior widebody Captains. Most pilots here at United will never be a widebody CA.