First, NO it was not all a competition between 9mm and .45. The revolver was king, and the market in the US for the wondernine was to replace revolvers, both for police work and the general public who thought a .355 bullet thrower was fine. Read many things back then when gun rags were all I had to go off about how 9mm is rather more cartridge than a .38, and of course the capacity. Someone had a term but it was along the lines of carrying 3 revolvers in your holster (multiples of 6).
It also is why the selective double action. Though opposite in actual action, that was available on most revolvers (thumb cock or pull straight through). A number of the wondernines came in DAO mode as well if you bought that and guess why? Because a lot of combat revolvers had the SA notch filed off (by design or after being placed into service by the department armories), so it was a thing for the revolver crowd.
These also often had magazine safeties, again because revolvers. Bad thinking, but the theory was: open the cylinder on a revolver, safe. Remove the magazine, also want to be safe so revolver-to-auto cops don't have to change the mindset, remember chambers.
The — very few — well informed gun writers of the time were entirely aware the wondernine thing was taking the world by storm, and very much included the P88, and the Steyr GB (friend had one: pretty nice and 18 rounds back then!), some FN HP updates, and the Star 28 as early concepts along these lines. A lot of these were submitted to the JSAAP trials in phase 2 or 3 as well, and I suspect that influenced the thinking that there was a single concept of a Modern Fighting Handgun to replace the venerable .45.
I never heard of things like the Glock, P7, VP70 et al referred to as wondernines at the time, though much of the googling now indicates they were. Selective DA hammers (not DAO, not strikers, etc) was the definition. In retrospect, I guess Glock et al sorta killed the term as a result.