I think people overhyped Tonga due to the NZ win, which as
@Matua said above was more a reflection of Kidwell and NZ's issues than it was of Tongas talent across the park.
The same NZ side lost to Fiji in a tryless game and managed to draw with Scotland the year before.
Now NZ have bounced back and got themselves a decent coach, this is an accurate reminder of where Tonga are really at. Best halves are fringe first graders and second stringers aren't halves.
Their player development is non-existent outside of poaching NZ and Aus players. It wasn't so long ago that Tonga was the worst of the Pacific Island sides.
Their current run can last a few more years yet, they have the core of a great team. But once the emotional high of 2017 wears off completely, will players start drifting back to Aus and NZ?
Without overreacting, I think they need to look at their pathways. Use the current high to get whatever funding necessary to make those pathways rock solid.
At 16s, 18s, and 23s level they need Tonga residents playing Tonga heritage. Get the best players out of those and have them playing Junior Aussies and Kiwis in front of NRL scouts.
They need born and bred Tongans because if NZ and Aus tighten up their system or Tonga go tier 1 then the poaching ends.
Without putting in the foundations now, Tonga will get eclipsed by Fiji and PNG.