Didn’t realize we had a dog forum..not gun dogs but maybe you all can help..

So I rescued a male and female pair, 50/50 Border Collie and Heeler.
They are smart dogs, and at six months they bounce off the walls.
We opted for the pair so they would run each other to death, and that is paying off, they play a lot, play rough.

The rescue lady said she didn’t agree with the practice of isolating them until all their parvo shots were completed, my vet sort of insisted on it.
Well now they have completed the shots, and I started taking them out in public, walking them downtown and trying to take them to dog parks to get them socialized.

At first they growled at everything and everybody, the male who is the smarter of the two is coming around to people, the female is still growling a lot more.

Other dogs? Forget about it, they want to fight with all dogs they come across. I don’t dare take them off the leash at the dog park.
The male right now is about 28 lbs and went after a 100 pound lab that towered over him, but tried a little too hard to play with him. Luckily I didn’t get bit by the lab when I pulled them apart!

I think I’m making progress with people, but other dogs I’m getting nowhere. I know cattle dogs can be chippy, but is there any advice how to get them more acceptable if being around other dogs? Maybe take them around solo instead instead as a pair??