still.. cougar prime overheats quite quickly even if chain-fired correctly. Basically it can hardly handle 2x CLRM10 +1x CLPL. The other LPL is a waste unless fighting under 150m.
The fact that each cLPL is in a separate arm gives you significantly more options for exposing a shallow profile of the mech while firing with the one cLPL that has LOS. Additionally, the range of motion you can get via free reticle and turning to look almost all the way behind you allows only one cLPL to fire when at maximum rotation.
Also, the usesfulness of the cLRM10's and the cLPL's are different situations of viability. Particularly if there's NARC or TAG on the field. I don't know how many times I've seen a NARC beacon go up while in a no-LRM equipped asset and sighed quietly to myself that I can't take advantage of it.
If you're running between cover elements and breaking LOS to your target with any regularity, then linked-firing both your cLPLs shouldn't cause any problems with heat.