How to get 2 dogs to walk together in the same direction?

[Endler32]

So I have been working on getting my lab x to walk better on the lead, all is fine until he sees someone then I struggle to hold him and he often pulls me over. I have another dog ( a Staffie ), she's not great on the lead, wears a harness, doesn't pull too hard but walks like a tank and often switches sides. I have been walking them individually whilst working hard to improve walks with the lab. Ideally I would like to be able to walk them together. I have just taken them out together and took them on a different walk heading in the opposite direction to where we normally go, both were confused so we're pulling me in all directions, I had to get them across a busy road and then through a gate into a field, it was a nightmare, both pulling me all over the place, I couldn't open the gate whilst trying to stop the dogs running in the road and pulling me with them. My Staffie has selective hearing so I have to have her on a lead, managed to let the lab off and he sat the other side of the gate waiting whilst I struggle to shut the gate, had a nice walk through fields and then had to go through it all again getting back out the gate and home. My hands are bruised. I'm not going to be able to walk them together am I? I think I'm kidding myself, if I can't control the lab on the lead im going to be up shit creek with both of them if we meet another dog