F9 or Allegiant both bring nothing but a huge unreliable dart boards with their networks.
While I agree that there are many F9 and G4 nonstop routes that would probably be dropped by WN in the event of a WN-F9 or WN-G4 merger, there are some F9 or G4 nonstop routes that might be viable on WN subsequent to a WN-F9 or WN-G4 merger.
In the event of an WN-F9 merger, WN would likely inherit a few F9 nonstop routes such as CVG-RSW, CVG-LAS, and DEN-DCA that would probably be kept by WN following a WN-F9 merger. There are also a few additional U.S. airports currently served by F9 but not by WN such as TYS, MIA, SRQ, and SYR that might possibly gain WN service in the event of a WN-F9 merger. There are also a few other F9 nonstop routes such as CLE-SEA, LAX-MCO, and ONT-MCO that might possibly be kept by WN in the event of a WN-F9 merger.
While many G4 routes would be dropped by WN in the event of a WN-G4 merger, there are some G4 nonstop routes that WN might keep in the event of a WN-G4 merger such as CHS-CMH (moved over from LCK), CHS-IND, CHS-SDF, CHS-PIT, CVG-AUS, CVG-LAS, CVG-MSY, BNA-DSM, BNA-GRR, BNA-RIC, and BNA-TUL.
Most of the nonstop routes that WN would be inheriting through a WN-F9 or WN-G4 merger could be added by WN without merging with F9, G4, or another airline.
AlaskaAir While it would Brings a huge expansion in SEA,PDX and SFO. LAX,SAN and SJC would all probably just see the overlapped network eliminated to raise revenue with less competition now in the market.
As far as AS Alaska network I don't see WN handling the schedule as efficient as AS does now.
If you think WN dismantled FL network in ATL horribly AS Alaska network would be 1000times worse.
One big difference between the WN-FL merger and a WN-AS merger is that ATL is the main hub for DL whereas SEA is a smaller DL hub that had only been around for 6 years. Another big difference is that STL currently has nonstop service out of SEA on WN but not on DL. WN had also served the SEA market for over 26 years, whereas WN did not serve ATL prior to the WN-FL merger.
There are also some domestic destinations outside of the Northwest or West Coast that have nonstop service out of SEA on AS but not on DL such as ABQ, BWI, CHS, CMH, DAL, DFW, ELP, IAH, OKC, OMA, PHL, PIT, SAT, DCA, and ICT.
In the event of a WN-AS merger, WN might possibly keep intra-Alaska routes that can support service on 737 aircraft with WN already serving some smaller markets in Hawaii, Texas, and the Florida Panhandle. WN had previously considered adding service to ANC, and WN had also said that ANC is one of the top U.S. markets not served by WN.
While there are some AS nonstop routes out of SEA to DL hub airports, East Coast destinations, or destinations not currently served by WN that might get dropped by WN in the event of a WN-AS merger, SEA would likely gain nonstop service to some additional destinations in Hawaii, the Midwest, and the South on WN if a WN-AS merger did happen.
AS's SEA hub is also bigger than any WN station, including its largest focus cities at MDW, DEN, and BWI. AS's SEA hub is also the largest non-US3 hub in the U.S.