I would think that the Morettes, being single lamp units, are not as deep at the point they cover the edge of the rad, thus giving the clearance required.
As the standard units are one big, moulded unit, they're going to be that much deeper, and so will foul the rad.
I can see from the pics that there's no space to move everything back, as the fans will start fouling on the belts.
I'd suggest that if you want the standard lights on, then something has to give.
Cutting the rad isn't an option, but what about cutting a notch out of the headlamp casing. Once you have enough clearance, the hole could be sealed up.
How about moving the fans to the front of the rad, and then moving the whole lot back an inch or so? Lots of work, but it's an idea....