What you didn’t highlight—perhaps for brevity—is the fact that the LH cars weren’t just normal, transverse front-wheel drive. They were longitude FWD. The engine sat way ahead of the front axle, mounted north-south, as in a traditional RWD car. The transmission sat over the wheels, and half shafts came out of either side of the bell housing, to meet each wheel (as this assembly also included the front differential, this made it a transaxle).
This wasn’t a Chrysler-first layout. GM had the longitude-FWD Unified Powerplant Package that was similar (and was used in some/most GM’s personal luxury coupes through 1985), only the engine sat *beside* the transmission. Honda did it on its high-end products between the late eighties and early 2000s, and Rover/Sterling borrowed it. But Audi was probably the original purveyor of this layout...and various Volkswagen, Audi, Porsche, Lamborghini and Bentley products continue to use the most recent version, which is designated as the Volkswagen Group MLB platform. It’s also similar to what Subaru does, although their cars use flat engines.
Aaaanyway, the thing about the Subaru and Audi setups is that they make it very easy to turn this layout into AWD. You see, the transmission is the bell shape of a traditional RWD car’s, and is mounted north-south as well. So all you really need to do is run a prop shaft off the back of the transmission to feed the rear differential and rear wheels. Subaru and Audi do this for most of their AWD cars.
The lore in the Mopar community is that, sometime in the late nineties, Chrysler experimented with doing the same. They allegedly built some LH prototypes that had AWD and even plain RWD (just by removing the halfshafts to the front wheels). There were supposedly some Chrysler cars in the 90s TV show “Viper” that had funny looking wheelbases and were in fact RWD LH prototypes.
Why Chrysler did not follow along with this path, I’m not sure. Given the different engine placements and completely separate rear suspension designs, I feel confident in saying that if LX was based on LH, it was probably only in the loosest sense. I suspect that Chrysler realized LH might be a dead end or too expensive to develop...and with new performance variants on the horizon (the SRT cars, and the return of the HEMI), borrowing from the Mercedes-Benz parts bin (I’m not criticizing here!) was a better way to go.
One particular example of how using a traditional longitude-RWD layout helped Chrysler is that they were straight up able to use the Mercedes-Benz 5AT; they would likely not have been able to do so (or would have had to specially adapt it) if they’d kept the engine-forward LH platform. What’s more, Chrysler was able to turn around and use Mercedes-Benz’ same transfer-case supplier, Magna Steyr, who supplied the LX cars with basically the same unit that the Mercedes-Benz AWD cars had. The R&D for making such a part that would fit onto the back of the Mercedes-Benz 5AT had already been done. That gave Chrysler’s LX cars an AWD option without a whole lot of development investment. That basic AWD system, I believe, lasted until the 2015 facelift of the second-gen consumer cars, where the Mercedes-Benz 5AT was retired in favor of the ZF 8AT. And you can still get it in the Charger Police Interceptor HEMI AWD (which retains the Mercedes-Benz 5AT).
