On Sat, 24 Feb 2018 06:21:07 +1100
A Walker Scott <[log in to unmask]> wrote:

> I know that three-vowle systems ar epretty common, but how weird is
> it for those three vowels to be /i/, /ɛ/ and /ɐ/ (or /a/)?

You get a "vertical" system in the NW Caucasian languages:
Abkhaz: ə a
Abaza & Kabard (Circassian): ɨ ə a
Ubykh: ə a
(although some say Circassian also only has 2 vowels. Elsewhere, there's
Margi (Chadic): ɨ a
E. Arrernte (Australian): ə a

The transcription conventions are all over the place: the two vowel
systems should really be /ɨ a/ and some people have written "e" for /ə/.
The allophones are very variable, with Arrernte having
/kɨ/ [ki]
/kʷɨ/ [kʊ, kɨ, ka/] !!
/ṯɨ/ [ṯæ] laminal alveolar t
/tɨ/ [tə] apical dental t

That's just 6 languages, and one (Ubykh) is now extinct!