Fighting could be barbaric, or it could be beautiful. It could be precise and meticulously planned, or it could be completely intuitive. Lex had seen many people whose fighting styles had left an impression on him.
Gisele, for example, was an exceptionally deadly fighter, yet her each and every movement was filled with grace and elegance. Even killing became an art when she did it. She was an unstoppable force, but a very fluid one as well.
Alexander was also someone who had his own distinct fighting style. Every attack, parry, block, or dodge was tinged with the aura of exceptional experience. To even fight with him, one would actually have to be much superior to him in either skill, which was unlikely, or surpass him by a large margin in strength and speed. Only then could an actual 'fight' occur. Otherwise, if anyone were even remotely close to him in ability, his endless experience would result in Alexander ending the fight in just a couple of moves.