Please, please let Bruce guard someone with those rules. You think he shuts Kobe down NOW?

He would absolutely, systematically destroy anyone he guarded.
PLEASE let Duncan maul whoever comes in the paint. He'd shut down any penetrating player in history.
You want to go by the old school rules? Fine. But if you unleash THIS Spurs team, which is BETTER on defense than teams were in the past when they were allowed to be so ungodly physical, if you allow THIS Spurs team to inflict their will physically? It would be boring. We'd destroy anything that came within reach of the lane. We've charateristically held teams to 87-90 PPG almost every season, with these so-called "soft" defensive rules that prevent our players from being physical.
I beg you to make that argument again. Unshackle these Spurs. Let the best defense in the NBA play as physical as it wants. The playoffs would be over before they start. We'd hold decent playoff teams to 70 PPG for a 7 game series.
Or, even scarier..... let the 1999 team play with those rules. My god... Duncan AND D-rob in the paint, doing as they please... no one would score on them.
The best part about your argument is that teams in the 80s were allowed to do all that and they STILL couldn't play defense. They STILL gave up open jumpers all over the court. If they gave Manu and Parker the space they did back then, they wouldn't be able to catch them to foul them. The Spurs of today play BETTER defense with more restrictive rules. Take those rules away and it would be frightening what we could do with hand-checking, hard fouls, etc.