
Well I am biased, but I have actually just posted about how great my breeds (Spins) are with terriers.
Although they completely different,( the terrier will be the boss :) the Spins require gentle handling to bring out in best of them as they are sensitive souls but they adored my parson.
They complement each other beautifully (he was a very feisty chap and they taught him to tolerate other creatures) hopefully I will have another rescue terrier as fab as him in the near future :)
Spins are fantastic dogs who tolerate everyone are gentle giants and extremely intelligent, always trying to second guess you. They do like their walks and respond well to training and of course their coat needs to be stripped, (although as your friend already has a terrier I am sure they are already used to this).
If you can put up with losing the comfiest spot in the house to them and the Spinny slop (which is like no other), then they are deffo the dog for your friend.
Please feel free to PM me for advice if you need to, or you could contact the Breed Club (ISCGB) and they will be able to guide your friend. HTH:) Dxxx