There actually some pretty viable reasons to not have two superhero with the same name. If given the option, the majority of fans or most likely going to choose The primary guy (in this case, Logan) over the replacement, which means you're going to cannibalize your sales. Hell, I love laura, but even I would choose Logan over her with a good creative team.
Plus, if we did this with EVERYONE (both thors, both captain Americas, all the hulks, all the captain marvels) we're creating a lot of redundancy. If im a fan of miles and Spiderman, even if I want both, im probably going to have to pick on or the other because I want to buy other marvel books too, plus those double moniker books are taking up slots for what could be new series for other characters.