It will be close, but you're right, it should work well enough either way. It's a PCIe 1x card for the USB 3.0 ports, that will cap it at that 2 Gb/s, rather than 5 Gb/s of the theoretical USB 3.0 limit. The wifi card is 600 mb/s total peak throughput, only 433 mb/s though on a single 5 ghz band. Slightly more than the USB 2.0 limit, way less than the practical speed of this USB 3.0 card, way way less than the theoretical speed of a full 3.0/3.1 port.
And now I've realized I've spent way too much time worrying about silly specs on a 12 year old PC that isn't even my kid's primary machine....