If I might offer an opinion based on English/English military language use as there are military cultural nuances a civilian English teacher would be unaware of but which I have picked up from coming from a military family and my own career as an Infantry Officer. (I do not feel I could comment on American/English)
On the word "tribal": The British Infantry is inherently tribal by nature and uses this term to describe our Regimental System of regionally recruited units. See British Army at
http://en.wikipedia.org/wiki/Regiment but it does not appear in regular unit titles.
But if we look further we can see extensive historical use by the British Army of locally raised formations - often identified by diverse terms such as xxx Frontier Force, xxx Scouts, xxx Legion etc. See
http://www.the-south-asian.com/April200 ... hans-1.htm
All could actually describe trained and equipped troops in well motivated and socially coherent units and still existing in the form of the Brigade of Ghurkhas and the Royal Gibraltar Regiment, as well as English, Scottish, Welsh and Irish units. However “Tribal” or “Levy” within a unit title would indicate a poorly trained and equipped indigenous force – using local techniques and best described as “Warriors”. “Soldier” implies a professional bearer of arms – be they a volunteer or conscript – in the service of the State.
Campaigner doesn’t mean fighter as the verb to campaign is not the same as to fight – it does have an aspect of durability and possibly being a veteran and the two have some linkage but neither would normally appear in a unit title. Warrior is similarly emotive and whilst used for our current Infantry Fighting Vehicle (indeed I was once held the job title of Warrior Captain!) it would indicate a primitive unit.
Okay, on to the nitty gritty – Aunuksen heimosoturipataljoona
On Olonets v Aunus – neither is English so in this case Aunus should be used as it features in the original unit title – one would not translate Royal Ghurkha Rifles as Royal Nepalese Rifles as it would lose the historical/cultural context. Additionally the Ceylon Regiment would not now be re-titled the Sri Lanka Regiment because the world has moved on
http://en.wikipedia.org/wiki/Sri_Lankan_Army
Pataljoona is easy as it has already been identified as Battalion.
So that leaves the tough bit heimo is clearly tribe or family and soturi is warrior but what is the intention in the original Finnish and can such a culturally embedded concept be translated? The use of ethnic in the title would be more American/English based on its use in the American Civil War to describe Black Regiments.
The training and ethos may make an investigation of the term militia pertinent. Militia, Fencibles and Yeomanry in England and Southern Scotland goes back to the Anglo-Saxon Fyrd and has a strong community based aspect.
http://www.nationalarchives.gov.uk/fami ... ilitia.htm
But again these were for local defence rather than normal deployment as a Regular Battalion.
In WW1 the British coined the term “Pals” – see
http://www.pals.org.uk/ - and this might go some way to convey the sentiment behind the unit title but still leaves something missing as it was a nickname rather than official title which was normally xxth Service Battalion, the xxth Foot and Mouth Regiment. So, in my opinion, an English/English Military translation would probably be Aususian Volunteer Battalion – “Aususian” would indicate the people (or folk) of Ausus, whereas Ausus would only indicate location, so you have the tribal part, and “Volunteer” shows a desire rather than an obligation to fight and thus a true warrior.
I hope that my opinion is of some use here.
On a separate point:
Ke.V = kengitysvarikko = Shoeing Depot
kengitysseppä = farrier.