if the bots work anything like they do in dota 2, which they probably do. they earn souls at a constant rate and dont actually rely on last hitting to get souls. its a weird mechanic i know but its to make bot games be a more consistent challenge no matter how they farm or not. notice how they all get it even your side lanes which i assume are also bots. or maybe its a bug idk i dont play bots so i wouldnt know