I'm not sure the 2001 Australia side would need 5 bowlers playing today imo. Batting sides are not lasting as many overs & averaging less than in previous eras which means the workload for the bowlers is lower.
That said & also asking
@ataraxia on this, if you were bowling to an AT test team how many overs are we expecting they would bat facing an AT bowling lineup?
All dependent on the day of course but with such a talented batting ceiling it could be 120+ overs. Could they also get rolled in less than a day? Possibly? But you'd expect that your pace bowlers can get through 20 overs a day & your spinner can bowl more than that. So you could cover a day with just 3 pacemen & a spinner.
Although whether it's ideal to have your spinner bowl that much on a pace friendly deck might be another thing.
I'm also unaware of when pace bowlers start losing their effectiveness in bowling load. But I think the big problem arises if the batting side lasts more than 4 sessions. Because your 4 bowlers are likely quite spent/losing their effectiveness by that point.
But is the trade off in having a 5th proper bowler over a Sobers worth it? How many more runs are you chasing with him bowling 15-20+ overs vs a top bowler? 20/30 runs more? You're losing that much or more with the trade off in batting imo. And if your main 4 AT bowlers are struggling to get them out is a 5th going to make the difference?