David Stifter wrote:

>> "Ninne, son of Matech, [one] of the Feini, went northwards
>> into the country of the Uladh with three horsemen to visit
>> friends,
> The OIr. text has triur marcach, which would literally
> translate as "with three horsemen" alright. But a few
> lines later the text goes "the two who were with Ninne",
> indicating that apart from Ninne there were only two men.
> So I wonder if the "triur" "three men" refers to the riders
> including Ninne, not excluding him as trasnlated in AL.

In further support of Ninne as one of the three, there
is this example from Thurneysen (p. 160):

'at·recht Mongán mórfessiur' "M. arose seven men",
i.e. "being one of seven" Imram Brain 56.14.