The wattage ratings on coolers are not something to rely on, I'm afraid. They're marketing speak, rather than anything actually properly measured or calibrated. A budget-ish air-cooler in a decent-but-budget case? That's never going to be great for cooling.
I'm curious: Can't remember if I've asked this before but is there a specific reason why PCS won't allow a 240mm radiator to be mounted in the Focus G case? I only ask as Fractal state it allows 240mm radiators in the roof and at the front...and I can't see a specific reason when I look at my case. Is it simply easier to have a blanket no than having it on a motherboard by motherboard basis?