This.

Not only can it be done, it has been done, and is done by OAL all the time. One of the factors that "makes it cheaper" to wreck QOL for on paper gains is granting marketing complete authority over all aspects of flt ops. They can't (and won't) be able to resist the temptation to save even small amounts of theoretical money by sending every fleet, including operationally redundant fleets, all from every operationally redundant base, in and out of every market like a shuffled deck of cards. That destroys the economies of scale within every category by slicing the pies into too many pieces and it becomes GIGO from there. Add in a fervorous desire to reduce hotel costs and a few other minor but powerful metrics and there's nothing left for an RCC to work with even if they had the power at that point.

The good news is there is some naturally occuring partial fixes on the way. The 88/90 being gone, and the 717 next (maybe) will grow existing categories while reducing some overlap. As long as we don't further dilute things too much (i.e. opening too many 220 bases too fast to save a few hotel pennies at the expense of everything else, etc) then that should help.

Its not that there shouldn't ever be new bases though; BOS can clearly support a NB base (as can MCO and a few others). JB has proven that beyond dispute. How can they do it and we can't? Because they only have 2 fleets flying out of those bases. DL can emulate that to a significant degree by picking a fleet or two and concentrating them in those O&D markets rather than trying to chase every penny to be found in hotel costs and trip productivity. That likely won't happen though because the lure of saving anything in theory is just too strong.

Really the only to fix the wrecked trips now is through PWA enhancements that provide the cost structure that forces the changes. As long as on paper trip credit and hotel costs reign supreme 1% commutability will remain the object at rest that stays at rest.