If i have to quote Boney constantly having to type out the response to similar, constant "elf could tear a human mage apart" that circularily happens all the fucking time in thread i will. The entire point of mankind transmuting their soul to their wind means that they are, in many ways, actually superior to elves in their chosen stick. Mathilde has several times demonstrated understanding of ulgu that utterly shattered elven minds. They had to call their best magical theorist to unpick it to something they could understand. So yes, it is up for debate.
So yeah, sure, a human will never master high magic cough cough Enchantress, Fozzrick cough cough but you damn well believe that Mathilde knows shit about ulgu none of these posers could even dream of having. This has been established at the very start. Elves have more institutional knowledge and better insight as species, and sure, they can probably punch higher on account of actually being able to do high magic if they invest centuries of study and passion into it, but at their chosen wind, mankind isn´t far behind, if at all.
EDIT:
So to expand, yes, the greatest of the Asur Archmages will probably trump even Algard in comprehensive magic knowledge, but even they probably won´t handle Ulgu much better than he does. They compensate by mastering all the other winds and weaving entire another school of magic on top of that, but guess what. We are not talking about Archmages here, we are visiting Nagarythe where people do shadowmurdering. And shadowmurdering is something Mathilde is already in the top 1%.