if you cap the number of entries....then the ninkasi award will just become pointless. Even with the "shotgun" approach there are ties for ninkasi every year. Plus, the best homebrew you ever make can score 23 in one competition and 45 in another.
If you want to be competitive for the NHC, then you have to show up to the game.
I think that capping entries at such a ridiculously low number like 4 will hurt the competitiveness of NHC. You might as well just assign everyone a lottery number and just do a drawing for the metals.
now for a better idea.....
most competitions are registered with the AHA. What if to enter NHC, you must win a gold in your category of that registered competition? How this might work is if a competition gets 500+ entries, then the AHA will give them 28 tickets to nationals. The competition organizers hand out those tickets to the first place. That way, the less experienced homebrewer gets feedback from the smaller competitions and the more competitive homebrewer needs to win first before "shotgunning" the first round.