Well yeah? Lancelot is capable of matching Numerals Gawain for half a day and still had more than enough stamina to defeat him at the end. If Gawain had it on indefinitely like he does in Camelot, that would change things but it doesn't as he normally doesn't have it.
Tristan was explicitly picked by Lancer Artoria rather than Mordred or Gareth to defend her Summer Casino and Arthur in Prototype Fragments states he's on par with Arash and from the 2nd Camelot movie, Tristan's raw strength is hilariously on par with most KoTR as well.
Mordred would be below him due to the fact for all of her power, she has no real skill with it and would get demolished in a fight(Gawain even states this in Tristan's Interlude he could defeat Mordred without Nightless and she doesn't disagree).
BUT:
Wrong, it's Bedivere whose the weakest KoTR by far, only getting by due to having Excalibur for an arm otherwise. Gareth explicitly is on par with Mordred and Agravain is above Bedivere.