The gold for Aspinall isn't that collection of contenders with a mix of recent wins and losses vs each other and other contenders Tom already beat. Aspinall didn't dethrone or beat a champion in the cage, it's why he wants to be an active champ and fight 4 times a year to establish credibility to his reign ASAP. Waiting to fight these guys only runs the risk of them continuing a round robin of fighting each other and collectively dropping their value as title challengers.
Look at how LHW champ Poatan was creating waves of hype over that group as a potential HW opponent for Jones or Aspinall, then he lost and now it's like no one cares. Gane and Jailton are barely holding interest as contenders only because they haven't lost to Tom yet, but their other losses in the division have people less interested. Might as well get them in there before they lose again like Gane basically did.
The "gold" for Tom, the big money fights are either guys coming from other orgs and establishing themselves as threats. A prospect rising up and being seen as a legit untarnished contender or the off chance that a former champ like Jones or Ngannou returns. The current top contenders are just grade A fodder for his highlight reel to set some divisional records and gain him some in-cage validation after not getting the Jones fight. Everyone expects these fights to happen and for Tom to win, but the excitement and big money will be from new guys on winning streaks who look like they might be unstoppable or a new kind of challenge.
I don't expect him to fight four times a year because negotiations and injuries create delays, but 2 years of cleaning out and lapping the top guys is plenty of time for new opposition to surface. That's how I see it.