thats actually not the dame at all really....
its exactly the same, how can you say its not?
i do it all the time, if you bet a team -1 and they win by 1 run you push and get your money back.
if you bet a team -1.5 and money line and they win by 1 run you win your money line bet which is the same amount as you would have placed on your -1.5 runline bet but lose it on that so you still get the same result.
i use mostly 3-4 books, only 1 book offers -1, pinny.
but i shop around and get the best possible price in both the money line and -1.5, sometimes using 2 different books to get this, money line bet in book 1 and runline bet in book 2.
all in all its exactly the same as betting -1 in the one book, prob get a better payout doing it the way i do it by sometimes using 2 books, as i do it most of the time betting a heavy fav.