As I said, the Lumbering Behemoth is an attempt to make Leman Russes more unique and different from other tanks, including IG tanks. It is not game breaking and Russes will take back seat in most tournament lists to units that do not have it. The Russes pay for LB by costing loads of points and since they're BS3 their shots are not all that reliable.
Fast rhino chassis has been a BA theme and they too pay a premium for the privilege. 15 points is over 10% increase even in the case of predators and vindicators, it is significant and balanced with SM equivalents. If fast vindicators were best in HS slot they'd actually appear in BA lists as often as Long Fangs appear in SW lists, which is not the case.>If they were +50pts then you might actually have an argument about them being balanced
I have an argument now and it's a good one. They come with expensive HQ's that either can't be transported in rhinos/razorbacks or take slots from purifiers. By no means are they autowin, never mind worth 50 points.
I don't know where you got the idea that I'm complaining about 5th edition nobs. I'm saying that you're whining about having to ask things or knowing what things do in tabletop, and that your argument about psychotrokes boils down to "I didn't know that unit can do that". Which is what a bad player who can't distinguish nobs form boyz during 3e would say about 3e nobs.
As for game mechanics, psychotroke-carriers obviously aren't overpowered or best choice for the slot. If they were, it would show in lists (again SW and long fangs are a good example).