RJJ just destroyed Jeff Lacey. Same wil happen ti AS. He's just using as a threat to White.
As accurate of a counter puncher Anderson is and as ridiculous as his head movement is as well, these measures of excellence that Anderson possesses are based on a standard of MMA fighters (particularly MW/LHW). However, compared to the world of professional boxing, I'm reluctant to think AS's counter punch timing, accuracy, power and evasive head movements would be as glorified. Silva can counter like that in the UFC because MMA fighters for the most part, either leave their punches hanging a bit too long, project too much or are just too slow (compared to a pro boxer), not to mention MMA guys more so then not, punch and block, rather then punch and (head or torso) dodge (there are exceptions, I said most part), which makes Anderson's counter striking even more effective.
Obviously, under MMA rules, AS would dominate a RJJ, however, if they fought under pure boxing rules, I'm fairly confident RJJ would shock AS not only with speed, but accuracy, power, evasiveness, punch defense, evasiveness, effective combinations and then back to speed.
I would LOOOOVE to see that fight (as much of a side show it appears to be on the surface), but it would be exciting. However, I'm not sure it would really resolve any real questions about MMA strikers vs Boxers because Silva is at a career pinnacle, while RJJ is far from his prime. Nonetheless, though I would give the fight to RJJ in this theoretical battle, it wouldn't shock me if Anderson pulled one out.
All my points are mostly speculation, so who knows how good Anderson really is, even compared to great boxers. I don't think this would happen any time soon though, Silva's current stock is too high and I don't think Dana feels that matches like a Silva/RJJ are very dignified (at least not for a champion of AS's current caliber).