Whippet front incisors removal, normal?

We have two Whippets, a five year old and a two and a half year old, both males. We used to brush their teeth every week but have upped it to every day in the past year or so.

Our younger one has had really bad breath as long as we've had him and we've tried various things to fix it. Took him to the vets today and the vet has advised that he needs all of his top front incisors removing ideally within the next 6 months. They've stated that due to him being a whippet he's prone to dental disease as well as the fact he has a slight overbite that his front teeth will only get worse.

The older dogs teeth are pretty much perfect no issues, I just want to check if it's normal for the younger ones teeth to have detioriated this badly and if it's normal to have them removed and if it will impact his QOL much or if there is anything else we can can do.