Am no big terrier man but heres a few things that you are told, when your young or just starting out in the game.
Borders are slow starters, well could be true but my nephew got one now that I got of a friend of mine at seven/eight months nailed rats first day out never been out before.
Lakelands/Fell Pats are all hard and can be only took to hole let off and dug to, I have seen them work cover bush rabbits, rat and taken beating.
JRT have got no working instinct left in them, I started off with little what we called, Queen Ann JRT you know ones that are from no working lines just