Speaking from experience, it’s a really bad idea.
You will naturally compare them. Superficial qualities may win you over and you could settle for the wrong reasons.
I was set up with two guys: the first, right on hashkafically and decent looking, the second, not exactly who I was looking for, but “drop dead gorgeous”. Guess who won out? I wound up dropping the drop dead gorgeous one later because it wasn’t a match, but by then, the other was “gone”.
I wasn’t even looking to date two at once. I had agreed to a date with one, when a friend called and pushed like mad for a date with the other. I figured what’s the harm? There’s no such thing as “just one date”. Each person has the potential to be your spouse. You need to be clear headed and block out all else.