So there have been some improvements with Tom Toms UTI cleared up. Positive step forward. Glad to hear that.
Fructosamine testing is more a piece of the puzzle than everything weighed together to make a decision on treating a cat.
Have you explained to the vet that now with 2 cats diagnosed as diabetic, you are trying to find a way to make this financially possible with alternatives to his treatment plan?
More on
Reference Ranges for Fructosamine Test and usefulness of the test here.
The W/d dry food is intended for weight loss, not specifically for diabetes. If your cat's are overweight, that is one food they can use. But your vet should have given you options that will also work well for diabetic cats AND any needed weight loss. Canned foods low in carbs are also lower in calories so can help a cat with weight loss. Plus the canned foods have lots of water which helps a diabetic cat keep hydrated since they are peeing such huge quantities.
Your vet may only have experience with a few insulins that are available to treat diabetic cats. So for that reason, may have done the

when you brought up another insulin he may have no familiarity with.
You are the advocate for your cat. You are the one making the decisions.
Let us know if there is anything else we can help with. Ok to post in this same thread, just change the thread title to something more appropriate.