As we learn at every CONNECTIONS....
There is no 'pathway' to a professional wargamer. The traditional (old) way was often folks who started with hex & counter wargames then were able to take their hobby and fit it into work. Look at Matt McCafrey or Larry Bond. Today much of the 'new blood' (yes, even Yuna) came up from academia and are looking for a social way to involve groups to get a decision discovery. Hence the rise of Matrix Games and the like.
Look around at any CONNECTIONS Learning Lab and there are a few hex & counter games. The younger crowd will often humor the olders by stopping by and talking. But the real games are the larger, multi-player, more Euro-like Matrix affairs. Even the professional wargamers for business don't talk hex & counter but a structured analytic approach.