Added up this designs. And you can take refer animation here: fav.me/d7araij
<da:thumb id="441332731"> . The particular red cannons are because of this: fav.me/d4mv9v6
<da:thumb id="280275378"> and fav.me/d4m77v7
<da:thumb id="279153043"> .when the x-77 turns into combat strategy, the cannons would be burden but they could add up to x-72 as more siege firepower. So a in-battlefield exchange could be performed.