The quality of the art is great, so please take this as intended to be helpful.
The average 'Mech is 10m-12m tall or thereabouts, with the tallest about 15m. Bird-legged designs like the Raven & Men Shen probably come down to 8m-10m.
The Raven is about 2.5 times as tall as the standing MechWarrior. This would put it between 4m-5m tall, based on humans being between 1.5m and 2m tall. So the scale just doesn't look quite right.
(I do think it's safe to assume that the standing MechWarrior is roughly next to the sitting one, so we can ignore depth effects).
That small quibble aside, I like them very much, and look forward to seeing more!