Fixed your post on 2 points - Taurens have 1.5 seconds (not accounting for server lag/latency) to swoop in and steal your herbs, since they herb in 0.5 seconds, and everyone else does it in 2 (unless Trolls have a hidden, slower herbing time)
And last i checked (which was yesterday), Herbing does NOT flag a herb as "in use" - so more than one person can still work on it