Actually, I may have overstated the case-- if it's all done right, the lamination idea will be strong enough. Let's say rather that there's more potential for a weak headstock if done the lamination way simply because there are more gluing surfaces that need to be prepped and glued.
Mostly, though, it's not about strength but about ease and aesthetics. When you've cut your headstock from the suggested lamination method, you'll have a lot more ways you can mess it up, and a lot more work to do to get it right, in terms of planing it flat and so forth.
As far as aesthetics, if it's painted on one side and has a headplate on the other it won't really matter I suppose, but in a natural finish, you'll get these weird lines going through it, where one laminated layer is glued into the next.
I'm not meaning to say it's an idea that "won't work". If you do it right, it should "work" fine. It just seems to me that you're thinking about it as a way of getting around having to do a scarf joint; however, there's no mystery to a scarf joint, it's not hard to do, the results are already field-tested and proven, and anyone can do it even if it's your first one. I can say this because I've only scarfed up one neck, and while I made a very minor flub, it was easily fixed and I could have taken about 2 minutes worth of steps to avoid that one flub.
Doing a scarf joint isn't anything to fret about.
Greg