Hi, I wish to start a topic to ask you wich setting you prefer in a Irish Trad band, with 6 costituents.
In my opinion:
-Fiddle
-Flute
-Uilleann pipe
-Guitar and vocal
-Bodhran and vocal (maybe female)
-Bouzouki
If it was my ideal group, I would have a harp and a bosca ceol rather than a guitar or bodhran or a bouzouki for that matter. The piper could double on whistle as well.
You forgot the clavinet.
I’ve been trying to form a piano, One row melodeon, and piccolo trio without success.
As far as bands go I quite like Triur. Fiddles and concertina, the odd bit of whistle.
I replaced the clavinet because I like more the bodhràn.
However, maybe a banjo could be cool.
Maybe consider the possibility it’s not the instruments but what the people playing them bring to the table.
The main argument here is sonority, not skills of singular players. Captain Obvious could say that all instruments played well are good in a band. 
Indeed, however the background sound made by different kind of instruments affect a lot the tune.
If your instrument includes a chanter you’re not allowed to join a sonority.
On a more serious note, I like a button accordion in the mix.
You consider the bodhran to be sonorous?
so·no·rous
[suh-nawr-uhs, -nohr-, son-er-uhs]
adjective
1.
giving out or capable of giving out a sound, especially a deep, resonant sound, as a thing or place: a sonorous cavern.
2.
loud, deep, or resonant, as a sound.
3.
rich and full in sound, as language or verse.
4.
high-flown; grandiloquent: a sonorous speech.
Giving out a deep resonant sound - sounds like a bodhran to me 
David
Hurdy-gurdy
Carnax
Spoons
I guess my connotation of sonorous was different than the actual definition…
Setting actual listening experience above some theoretical construct I would say http://www.dervish.ie/
???
Or
http://m.youtube.com/watch?v=GxKeYZb-IB8&desktop_uri=%2Fwatch%3Fv%3DGxKeYZb-IB8
Rumor has it she can sing a little as well.
Yes, great, but I count 7 there ! I haven’t seen Danu live yet and I chose Dervish as a substantive answer to the OP because I like that sort of ‘melody instrument rich’ line up.
I don’t recognize the flute player. He may be a former member or a guest. When I saw Danu last year they were six. I agreed with your “substantive” approach, which is why I followed suit.