I actually see one problem.
For group games, the entire number of threads allowed is x2(I believe) to the number of active members of the group. If variations of one x one threads take place, then that may cause other problems.
Alternative solution to this would be
The individuals have only one thread each to track all of their progress and matches. Quick post links within the title of the initial post can help guide between what may be practice matches or career driven matches. I don't see too much of a problem here, since 1. Practices are generally limited to one, minus the start bonus and 2. It helps trim down threads if people choose to make an additional character or if GM wants to place other event places for things to do outside of combat system.
Alternatively a separate thread for training could be used for everyone, but with so much posting going on within a single compact area, it may get too complicated to track everything.
If you choose not to do other areas, then each player could have one thread for training and one thread of their own for sparring; however, this may not allowed for additional threads such as OOC, Game Info, or Character Database given such and also would deny individuals of being able to do multiple characters since the E rule applies to active members of the group and not by number of characters by said members.