Apart from Steve Waugh at the start of his career, those names are all part timers. I wouldn't any of put them in the 5th bowler category.
The most recent examples of 5th bowlers would be Stokes, Green, de Grandhomme, Watson types.
Those part timers all filled the role of 5th bowlers though, that's the point. Greg Chappell etc etc. as well.
I'll phrase it this way.
If practice elevated average cordons to very good, we wouldn't have as many average cordons as we do today, and through out history.
And there's countless stories of bowlers getting into the nets and improving their ability to stay at the cease. They're not world beaters but they hang around longer.
I'll use AT names here, but only discussing their secondary traits.
Hammond is one here where it was well litigated that he's below all rounder status. Same with guys like Cummins or Marshall.
On the average test team, or even a hypothetical above. I am more comfortable with. Hammond as my fifth bowler, and a Marshall / Wasim / Warne / Cummins at no. 8, than I would be with a Kohli / Khawaja at 2nd slip for my team.
Hammond isn't going to actively hurt the team (Subz even has him in his 2nd all time team as the all rounder) in any way and will pick up the odd wicket, the batsmen I mentioned have all filled that role in tests for successful teams and performed the job more than admirably. I do need a specialist at 2nd though, too many chances go there.
To put a bow on it, and this may be only me..for a regular team, I'm more willing to make a bit of a sacrifice to have a Richie Richardson at 5, over say an Inzamam in my batting lineup, than I would be willing to have an all out 5th bowling all rounder (as I've argued for a while now) like say a Miller over Hammond for a 2nd AT XI. Because if Miller is your 5th option, you've got the bowling covered and you're loosing too much in the batting.