There should be tunic-like garments for some Irish and Pictish warriors. While many miniatures in the Book of Kells f.e. dated about 800 AD show soldiers with what seemed to be knee length narrow breeches there also are some with leines only, mostly wealthier persons perhaps. Pictish warriors are mainly depicted with long or short tunics, f.e. on the Stone of Rhynie http://www.undiscoveredscotland.co.uk/aberdeen/rhynieman/ or the Brough of Birsay http://canmore.rcahms.gov.uk/en/site/1797/digital_images/brough+of+birsay+pictish+symbol+stone/. Some should be barefoot, some with shoes, some without beards and some with beards, according to the stone pictures.
There is a thesis that the Picts also wore knee length breeches similar to the low rank Irish warriors in the Book of Kells, that the Book of Kells resembles partly Pictish warriors and that the breeches or shoes are not visible on most or the stones because they were painted on. I find this thesis lame because on most stones all the important clothing structures are carved, why wouldn't only the breeches (or shoes) be painted?