Using 2 different LDO with the same voltage in the same application
Short answer: Yes.

Slightly longer answer:

You would need to make sure your 3.3V LDO has it's required passive parts (capacitors, resistors, etc).

You would also have to watch out how much current you are draining from the RPi's 5v/USB line. Older Rev 1 boards have 140mA Poly Fuses on the USB ports. Old and New model RPis have a 700mA Poly Fuse on the power in usb line. And they both have undersized capacitors, which can cause an issue with Voltage Sag resetting the RPi. Too much current draw, and you will have issues. Too much inrush draw, and you will have issues.