Wow! These are going to benefit you big time already. Awesome job! I am happy you sticked to the "reusing" bit and I think you managed to maintain a good sense for scale. If you want to revisit these and do minor changes I would suggest you to do the following:

Thicken up some of the thinner rails on the insectoid one's legs. They seem a bit flimsy.
I love the way you think about the armor parts. The 4-legged robot could use stronger back legs, especially at the top joint I would add volume. This is where you could introduce more heavy armor that would protect it from the side for instance. Take another look at the turrets maybe and have a play with assymetric placement of the barrel in its composition and for the insectoid version I would make the barrel either shorter and/or thicker. I personally would love to see you pushing the mini tank through the course but ofc it is all up to you.

This is going to be great!

Soo cool Florian!

Very interesting!