I have a Kerry Blue (cross probably) rescue who was obviously not socialised with other dogs and I've had to work on her dog aggression. Have to say it's worked well and she's good now but not 100% and probably never will be. I don't let her off lead either as she has a really strong prey drive and zero recall when she gets stuck into something (or couldn't be bothered). She is very clever so very trainable but also incredibly headstrong so

so she'll only be trained if she wants to be

She can also move very fast and jump very high. I still haven't managed to make my fences high enough! While some of the issues are generally recognised Kerry Blue traits I do think they have emerged because of her neglected background so I daresay training and socialisation from the outset would offset these.
That all sounds very negative so I'll add the positives... she is playful, funny, full of goofy character and most importantly for me fantastic with the kids (9 and 6) and they love her to bits