Why not use (o)combë?

I think the English word "group" has several meanings, that's why it would have more than one equivalent in Quenya. I've been using hostalë for a group of people, for a while.

Well, groups usually consist of people or mobile creatures and not things. Hence rather e.g. *o-quén-ë (for those who for some reason don't like the attested or modified forms from KHOTH). A synonym *(y)onámossë even offers thoughts about group mentality..

+Paul Strack it was more like a theoretical question, as in "does any noun + -sta mean a group of those nouns > hence *quasta a 'group' in itself? quenesta a group of people, a team?"

E.g. would/could ñaurosta mean "a wolfpack".

+Tamas Ferencz Unlike Sindarin ath, I doubt sta is used as a general collective suffix. None of the attested examples have this meaning.

In fact, the closest general meaning in Quenya seems to be “part”, as (for example) the use of -sta in fractions.

+Paul Strack there are many stas... I am taking about this one: eldamo.org - Eldamo : Middle Quenya : -sta¹

I think sorasta may belong to the same group of nouns, beside tengwesta that you cite on the Eldamo entry.

+Tamas Ferencz I get which sta you talking about. I just don’t think Quenya used it that way. The linked entry above is part of a discussion on the origin of the collective suffix ath in Noldorin/Sindarin. If that suffix survived in Quenya, I think it’s original collective meaning would have been lost, and it would serve only as an abstract noun suffix in isolated cases like tengwesta (and maybe sorasta).

To put it differently, I think a general collective suffix is too “Sindarinish” and shouldn’t be part of Quenya.

+Paul Strack rebuke accepted:)