If the Cowboys had it to do over again (Spoilers)....
They shouldn't have shot his brother.
Just sayin...
"If you leave one wolf alive then the sheep are never safe."
Game of Thrones
If the Cowboys wanted to hit the Earps, then they needed to hit them all at once, or at least on the same night. They did kind of try to do that by hitting Morgan, Virgil, and shooting at the women, but they left Wyatt alone which was probably the one person you most needed to hit.