It doesn't at all surprise me to hear this from a Broncos fan. These big, national sponsors that you talk about are exactly the big market sponsors that the little clubs will never get a look-in for. Why would a national-profile sponsor want to sponsor Jarrod Mullen when they can sponsor a player that will get them 10x the exposure?
Additionally, as you've pointed out, only the absolute cream of the crop can get attention from said big sponsors. When you're playing for QLD, NSW or Australia, yeah, you tend to get a bit more exposure.
Even more than that - big market teams tend to dominate the free to air match time slots (could be because.. oh I dunno... they operate in a bigger market, with more supporters and ergo more exposure to potential sponsors). Dominating the free-to-air schedule only further works to increase the gap as sponsors gravitate towards the teams that do have the most exposure for their players. What logically follows from this is that sponsors get more exposure for themselves, which leads to more value for their investment, which means they can justify larger spend on sponsorships for such players.
None of this is really rocket science, anyone who thinks about this for more than a minute or 2 should come to the same conclusion. It all combines and amounts to an extremely unfair, unbalanced system.
One simple rule they could put in place to somewhat mitigate these issues is put a cap on the percentage of a contract that can include 3rd party sponsors. If a 3rd party sponsorship couldn't amount to more than 20 or 30% of a players contract, the little guys might be able to get more of a look-in. Of course, by extension this essentially sets a cap on third party agreements (to 20-30% of the salary cap total, using my example) and, in fact, includes TPA's as a part of the salary cap system, rather than completely outside it.
I've heard that the Milford deal for the Broncos includes more money outside the cap than in it. There's no way a Newcastle or a Canberra can ever, or will ever compete with that on any contract bar MAYBE an already established superstar who can attract national/international sponsorship off their own bat. Even then, as I've illustrated, a player is worth more to a sponsor playing for a big market team than a small market team.
