Where did you get the latest inner panels? That’s interesting that they’re too short front-to-back. If they’re too high that would make them miss the toe board if lined up to the door pillar like it should be.
I would at least get the outer cowl located on the door pillar before installing the inner-to-outer cowl piece. That inner-to-outer is going to take the most “adjustment”. And it’s important to get the door opening set first.