Geez, if that were the case, my civvie (non-diabetic ca)t would be in extremely high numbers all the time!!
If I may make a suggestion or two....
Since you're using Lantus, please take a look at the sticky notes that are at the top of the
Lantus board. With Lantus dosing, there are 2 methods that are used. Depending on which method you opt for, you want to increase the dose more often than it looks like you're doing. Holding a dose that isn't getting your kitty into better numbers (and you're doing a great job testing) can cause glucose toxicity to develop. The term sounds a lot worse than it is. It basically means that your cat become acclimated to being in high numbers. As a result, it can be more challenging to get those numbers to come down. The highs become the "new normal."
Lantus dosing is based on the nadir -- the lowest point in the cycle. If you are testing primarily at shot times, you have no idea how low the dose is bringing your cat's numbers. It's entirely possible for a cat to start the cycle with numbers in the 400s, drop into the 40s, and bounce back to the 400s by shot time. The drop to the lower numbers would necessitate a dose reduction but if you didn't catch the drop, you'd likely be increasing the dose.
Please get at least one test before you go to bed every night. Many cats experience lower numbers during the PM cycle. Without PM tests, you're missing half of your data.
To be honest, it looks like Mr. Moonie need more insulin.