Queen has no idea it seems how many humans hace fire abilities in this series. let’s go down the list
-Pearl
-Lucci
-Sanji
-Zoro
-luffy
-Doflamingo
-katakuri
-holdem
-black maria
-pugman
-kin’emon
No one you mentioned ignites their body then sustains the flame.
Pearl - Uses friction to set his suit on fire
Lucci - Non Canon
Zoro - Uses sword style that allows him to cut fire
Kinemon - Uses sword style that allows him to cut fire and ignite his sword slashes
Doflamingo - Uses friction via haki to heat up his strings
Holdem - Devil fruit
Pugman - Running so fast creating friction (Luffy did it in punk hazard)
Black Maria - Devil Fruit
Katakuri - Air resistance ignites the attack for his grilled Mochi due to high velocity
Luffy - Uses the insane amount of oxygen in his arm due to gear two and friction from haki he ignites it for a single attack
The difference between these and Sanji are literally night and day. Either someone’s igniting a piece of equipment, or they’re creating fire for a single attack that then disappears, or they use a devil fruit.
Sanjis Diable Jambe ignites his body, then sustains it for however long he desires, then is able to snuff itself out once he’s done. Using fire and being able to control it like Sanji are not the same