IT shouldn't be the ones picking the retention policy for data. That needs to be decided by the legal team.
Google Nearline is cheaper (no access fees) and much simpler pricing structure. Glacier is just ridiculous in its pricing complexity and restrictions.Archiving onto Amazon Glacier should fit 99.9% of business data archiving requirements. Outside of that you have stuff like Iron Mountain if you really want to use tapes.
If the internet connection isn't good enough to archive to a cloud service then get that upgraded as you're just holding the business back in so many other ways without decent connectivity.
In my experience small businesses are TERRIBLE at managing tape backups. What I've seen multiple times, is that something is wrong with the backups, the employee dutifully puts in a new tape every day, but in fact they haven't had backups for months. In one place, the receptionist had been taking the tapes home every night, but they hadn't had a valid backup for something like 18 months.
Google Nearline is cheaper (no access fees) and much simpler pricing structure. Glacier is just ridiculous in its pricing complexity and restrictions.
https://cloud.google.com/storage-nearline/