Beyond the whole 'is a wizard' thing, he did have a death & resurrection seen.

As for Sanya - Aragorn, flat out, badass sword plus blood of ancients kings, like the other knights

I think before delving into the others it is worth reminding that during all of LotR the Fellowship is only together and whole for a very short interval, in six total books it gets formed during book 2 chapter 3 and dissolved at the end of book 2 ch 5 when Gandalf fights the Balrog. Out of the 9 who hit Chichen Itza only Harry and Sanya really fit closely any of the 9 walkers, with a loose match for Legolas to Lea, both being ancient elves.

so:
Harry - Gandalf
Sanya - Aragorn
Leanne - Legolas

I think at this point we have to look at the remaining 6 walkers in terms of character, then compare

Frodo - Brave and determined and very clever compared to the other hobbits, set off on a suicide quest.
Sam - Loyal and steadfast to Frodo, went with him

So Sam needs to be a loyal to whoever is Frodo, and we could do Harry/Molly or Harry/Mouse for that one we've used Harry up. But we have Molly/Mouse, Mouse fits Sam easily enough and in regard to Molly too, plus Frodo and Bilbo before him are in certain ways non-magical Gandalf's protégées.

Molly - Frodo
Mouse - Sam

That leaves us Gimli, Pippin, Merry, and Boromir to match to Thomas, Susan, Martin, and Murphy. Murphy fits any short fighter which gives us Merry and Gimli for Murphy. So we should ask who else could be a Gimli or Merry? Boromir being best known for being over-proud, betraying the party, the sacrificing his life to make up for it can be any of the remainder except Martin who is definitely not blinded by pride. He didn't sacrifice his life to pay for his treachery either, sacrificing his life was part of his treachery to his allies. So that leaves us Susan and Thomas as Boromir. The death part doesn't matter over-much, symmetry on that is screwed regardless since Susan, Martin, and harry all die in the book. Susan knowingly lets herself be killed and does die, plus she has an over-proud streak causing problems the whole way. It probably isn't fair to say the whole war was her fault, but she went to sate her curiosity back in book 3 in spite of huge and serious warnings and then in book 5 she and Martin show up to try to ensure the war continues. So susan gets Boromir.

Meaning we now need to decide if Martin or Thomas is a better match for Pippin. And that's easy, Thomas is much more cheerful and kown to stumble into trouble, whereas Martin is dour.

Thomas - Pippin
Martin - Gimli
Murphy - Merry
Susan - Boromir
Molly - Frodo
Mouse - Sam
Harry - Gandalf
Sanya - Aragorn
Leanne - Legolas

That's my pick, though I think it would be hard to find any other band of heroes of the right size that was a worse fit for the Fellowship.