Mostly, the idea can be found at the bottom of smokin' holes all over the world, where expensive, gold-plated Western-built (mostly US-built) aircraft have laid the wood to the light, cheap, mass-employed aircraft produced for Third World air forces that can't afford the good stuff.
As far as being able to lose four out of five of your fleet (seeing as how that means you'll still have 20% of your aircraft left), can you imagine ANY commander allowing that to happen to a country's entire air force? Can you imagine any air force being enthusistic about that doctrine, and employing itself willingly in a conflict?
No. If you're going to have an air force at all, you have to absolutely assure that it's going to be the best one, and that assurance needs to be by such a huge margin that there can be no doubt at all that it will prevail in the likely - or even PROBABLE - conflict. Anything else is an enormous waste of money, because even an inferior air force is hugely expensive. If it can't win, it's ruinously so. As the saying goes, 'The most expensive thing in the world is having the second-best air force'.
SO buying large numbers of crappy aircraft (I know, I know; not all light, cheap aircraft are 'crappy', but neither are they good bets against top-of-the-line aircraft) just means you make it easy for your opponent to run up the score on you, making it that much easier to break your will to continue the overall conflict, in ANY sphere. Ask any Egyptian, Syrian or Israeli air force leader.
Also, the most expensive component of ANY aircraft, light or heavy, cheap or expensive, is the CREW. So, having five times MORE pilots is cutting into all them savings, and with all those airframes to maintain (even accounting for their supposed simplicity) is going to require more maintainers, more ramp and hangar space, more spares, more airborne controllers, more airfield controllers, more more more...
And about ten times more Rescue and Recovery personnel and aircraft, to pick up the survivors of the 80% of your force that got zapped.
Nope. Buy top-of-the-line tech, buy enough of it, and win your wars against the low-tech/low performance cheapskates that wanted a big 'brag' number of airframes.