Does the drive have it’s own powersupply? Powering two drives via the USB ports is quite unlikely.
If you talk about performance the USB 2.0 port would for sure be a bottle neck to access both drives at the same time. But if you just use them on that Pi then you would at least not fight against the Ethernet also running on the USB port.
So long story short if you want to share files to multiple sources on the network at the same time a dedicated NAS will beat the Pi.