Emma has the >.

>So, unlike English where the use of the "we two" or "we three" is used for
>specificity, this form is simply to differentiate between we two as opposed
>to "me and many others"?

Exactly. But the number can still be tacked on for emphasis or some special
effect.

vit tveir = we two (masculine)
vit tvær = we two (feminine)
vit tvau = we two (neuter - a man and a woman)

In Þrymskviða when Þórr has been dressed up as Freyja
and Loki has offered to be his maid, Loki says:

"Vit skulum aka tvau í Jötunheima."

Meaning:

"We two shall drive to Jötunheimar."

But the form Loki uses is "vit tvau" which means (as shown above)
"we two - a man and a woman". So Loki is jokingly suggesting either
he himself is a woman or Þórr is.

This subtle detail is impossible to translate into English.

Regards,
Haukur