Is the philly shell okay to use in this circumstance?

I (5’6) have a long sparring partner (5’10) same weight. He doesnt have great technical skill but he is hard to hit him because whenever i fire somthing he just steps back like 2 feet. And when i DO get him in a corner, he teeps the crap out of me. Makes me want to throw up. I notice however that when i put up a philly shell his teeps dont work. And due to my stance being southpaw and his orthodox he cant easily leg kick my lead leg. I know useing this stance would get some criticism , considering that it’s not a muay thai stance. Would it be okay in this instance? If not what do i do?