Keep in mind that there cannot be that many more of the Lannister Army left.
They left part of the lesser Army at Casterly Rock to be easily beaten by the Unsully.
Now Danny, the dragon and Dothraki took out a great deal of the army that Jamie And Lord Tarly were in charge of.
The preview for the next Episode has The Dragon in the background and Danny in the foreground telling people to bend a knee...now it could be a different group but it looks like it was on the ruins of the current battle field and I have to imagine she is talking to the survivors...aka rest of the Lanniseter Army or possibly Bronn, Dickon and ...maybe even Jamie.
I think this would get Bronn at the least to reunite with Tyrion but at first I did not think that viable with Bronn being a sell sword and Danny might not like his dirty mouth...but she liked the last sell sword that pledged to her and he talked dirty so who knows.
Also Bronn has been asking for a Castle and the lannisters keep promising but not delivering on that...maybe Tyrion will.
Of course..>I like Bronn so I am probably making any excuse to have him survive...which she might be against since he was the one who used the weapon against her and her dragon.