Hellya,that won't work.Knights are well below samurai,and so they won't work.Samurai is better for clearing out the enmies so you can use green giants to beat the boss without the orgianisms in an army.
Needs a skirmish mode,and you can set the amount of enemy colonies,maximum is 3 enemies,not including you.You'd pick from Roaches,beetles,ants or grasshoppers,and maybe a mode where YOU are the larva in the final stage,and you get to control the queen and attempt to destroy the enemies,using your queen.
On level 8,as the roaches/ants [and I suppose it works for the beetles too,and the grasshoppers as well if anyone figures out how to get them] if you rush the enemies fast enough,then you can break through without having to wait,and then you can overwhelm him quickly.May hurt your score though.