I use a Vega long neck (5 string) for the Celtic music we play ... but I can't say I follow any discipline at all. I use some brushing, some three finger picking - usually a combination of both. The front of my nail brushing down on a string drives a loud melody line - and that method in combination with three fingered picking or thumb and finger brushing produces some interesting sounds that work well for us. I can't say it fits a classic Celtic style - but I like it.