From their weights and probable ages it definitely doesn't sound like you're overfeeding them. Some of mine are about the same age and they've been fed every 4 or 5 days for the most part.

To get the one off mouse hoppers and onto rats you can try getting both a very small mouse hopper and a very small rat pup. Feed the mouse first, then while the snake is still in feeding mode, drop the rat pup in. May work, may not.