Aspinall is clear as day one of the best HWs to come along in the past 5 years (him and Gane, somehow they haven't fought yet but they're the clear two best).
They both debuted around 5 years ago. Gane fearlessly climbed the ranks at light speed, with a title shot less than 2.5 years after his UFC debut (where he was shellacking Ngannou on the feet effortlessly like no one ever had before, but lost due to not being prepared for Ngannou's wrestling pivot).
Tom on the other hand hasn't fought anyone near the level of Ngannou yet, 5 years into his UFC debut. He won the title off his win over Sergei, who is a good reference point because he's a type fighter in today's division yet got streamrolled by a 38 year old way past prime Overeem inside a round.
Which brings me to the thread topic. Aspinall has been outside of the first round in only one UFC fight, and there's a reason for that, it's because he fought a HW from the better days of the division. Even though Arlovski was 42 and way past his prime, he gave Tom his toughest fight in the UFC so far. It really makes you wonder if Tom could've hung with that era.
Carwin: Shane had an incredible chin so good luck knocking him out in a round like this new generation. What does Tom do when his only gameplan doesn't work? Plus Shane had an collegiate champion wrestling background so the takedown wouldn't be an option either. Shane catches him with his legendary power and puts Tom to sleep. Yes JDS, who is a similar fighter to Tom at first glance, destroyed Carwin, but don't forget JDS back then had a granite chin and elite TDD, neither of which Tom has.
Cain: Destroys Tom similar to JDS 2 and 3 fights, except much GNP since Tom's TDD isn't as good.
JDS: Great fight, similar styles, coin toss.
Stipe: Can hang with Tom on the feet but way better wrestling. Stipe uses the same gameplan he used vs Hunt and wins a dominant UD, especially since Tom probably gasses fast from his explosive style and Stipe could go for days.
Werdum: Tom would probably win this fight due to Werdum's poor wrestling. Huge win for Aspinall as Werdum was a champ.
Overeem: I think Tom catches him and Overeem can't take the shots. Another huge win.
Brock: Unless Tom catches him early, Brock gets the takedown and absolutely mauls Aspinall on the ground. Stuart dominated Tom in wrestling and ground, and Brock was super elite in both areas. One of the best top games we've ever seen plus unlimited cardio.
Ngannou: Rock em sock em robots but Ngannou had an unbreak chin back then and more power. Tom can't play that game with Ngannou, he gets brutally slept.
So Tom goes 2-5 or at best 3-4 in the division if he manages to beat JDS. Either way it's a losing record and he's not ranked in the top 10. Tom is great for his current division but in see him very similar to a Miguel Torres, looks amazing for his division but it's more due to the level of competition.