Finland's fighter competition is different. (I'm just learning about this, so please feel free to correct any errors.)
Rather than specifying a number of fighters, they are specifying $12B budget. Each contender is expected to offer whatever number of fighters they can fit within the budget, and are required to include weapons and missiles. So Saab, for example, is offering 64 Gripen, 2 Global Eye AWACS, and a bunch of missiles including the Taurus KEPD 350 cruise missile. Boeing is offering the 50 F-18E/F fighter, 18 EA-18 Growlers, and the JASSM-ER cruise missile.
On advantage of doing this is you get an integrated package at a known budget. A disadvantage is that you cannot pick and choose this plane but that missile. Also, you don't get to specify the number of aircraft being purchased.
The F-16 was disqualified as not meeting technical requirements. I don't know that the F-15 ever put in a bid. The Mig-29 was disqualified because.
Do other militaries do this? I've not heard of western nation packaging missiles with airplanes, and not specifying the quantity but the budget.
All of this is covered by the amazing blogger Corporal Frisk
Overview - https://corporalfrisk.com/2021/05/02/stop-bafo-time/
F-18 -- https://corporalfrisk.com/2021/08/09/bo
F-35 -- https://corporalfrisk.com/2021/06/25/lifting-the-fog/
Eurofighter - https://corporalfrisk.com/2021/08/12/hi
Rafale - https://corporalfrisk.com/tag/dassault-rafale/
Gripen - https://corporalfrisk.com/2018/07/22/sc
Strangely, in July Bettson (a casino) put odds on the winner if you want to place a bet.
F-35 35 %
F/A-18E/F 25 %
JAS 39E/F 20 %
Eurofighter 12 %