I can't see Brock putting Ryback over.
I could see Brock interfering at HITC because it would preserve Rybacks' streak and would make sense with the Heyman alliance.
But I don't see the rumble becoming a Triple Threat. IMO I see Punk dropping the title to Rock at the Rumble, (although I wouldn't like to see it), with Rock putting Cena over finally at 'Mania when he drops the title.
I could see that leading to Lesnar Vs Ryback at 'mania though, with Ryback winning after Lesnar broke his streak at one of the prior PPV's.
They could start to emphasise Punk's Muay Thai background more and more before starting the feud with Lesnar, doesn't Cain Velasquez use Muay Thai strikes? With enough time before the fight and the right sort of angle could make it seem like Punk has a chance against Brock, and Brock should know how to sell being taken apart by a better striker right?
I'd think he'd feel nervous, and he'd back off and it might remind him to sell.
I guess if he does get his Wrestlemania moment with Taker like the two of them tried to set up in the past he could learn what happens to people who don't sell, I'm sure I saw taker delivering a vicious chokeslam to someone who tried to sandbag him in the past but I can't remember who right now