If you have the option, more Guard would be better for you than the knights and 10 skinks. 10 more Guard will beef those squads up. You can rely on the Chameleon Skinks and deep striking Rippers to disrupt the backline and provide some objective "sneakiness." With 10 more Guard you can control the midfield with a bigger presence and staying power. If you did this, it would be almost identical to LordRibbit's list. He put up a great Batrep. Check it out!
Also, as good as the Bastiladon is, it's dmg will be less reliable without rerolls from a formation or skink chief.