[Garen]

My $0.02: technically nothing "wrong" from a function perspective, however: The front cooler will get fresh cool air, and dump its spent, hotter, and slower air into the cooler on row two. Residual heat from both would have a soaking effect as well on each other.

However, if you look at the stack-up of coolers on modern cars, sometimes you have a radiator, with a trans or power steering cooler in front of it, and there is usually an air conditioning condenser in the middle of all of that. These are usually package-driven decisions, no doubt having them separate with good airflow would allow the engineering team to shrink the size of each cooler due to more efficient performance.

If you do it, make sure you feed the stack with a decent, sealed, dedicated fresh air ductwork so at least you get some velocity at speed, where the fan will generally be useless and in fact, in the way. Anything over 30-40mph. Same goes for an efficient fan to help pull enough air through at idle / city traffic speeds. If you buy lightweight plumbing like the Starlight hose from Aeroquip the weight hit won't be huge, if you use hard plumbing that you yourself fab-up and small hose lengths as connectors your cost will be lower. Then there's the center-mount option for one of the coolers but that would add an aesthetic change to your car that I'm not sure would be a positive.

Basically, the more efficient the flow to and through the heat exchanger, the smaller it can be. 956/962s had really thick intercoolers, but the trend has moved on from there in modern race cars, as has the tube/fin/basic design of intercoolers themselves. In a nutshell it's about efficiency in getting cooling air to go through the exchanger, with "bad" air, the coolers will have to grow to do their job through surface area, heat rejection.

Why not run just one of them to start, and maybe with good ducting it's enough, due to the perceived higher efficiency of the CSF core.