Thanks to the both of you.
Just to be clear, the proper reading is “locis natis ad equestrem pugnam”, right? I had it “spem nactus ad equestrem pugnam” in the translation, which I didn’t update after I thought of the other because “locis natis etc.” is harder to render into English.
“locis natis ad equestrem pugnam”,
Yes "at a place produced by nature for cavalry warfare. "
In translating you may want to turn the whole thing round. At a place very suitable for cavalry fighting, in which his greatest strength lay, H. hoped the Consuls would provide an opportunity for fighting. etc