I feel there should be a good ratio of such wallet types, I just don't know which ratio would be best.
i use 1 android bitcoin wallet (with 200mBTC).
i use "many" cold wallet (separate) from bitcoin core.
wallets are stored in 2 hard drive and 5 USB key with many folder by date (10 folders with the same "many" wallets increase by 1 every new wallet created).
You can corrupt 1 file ... but you can't corrupt 100 files separate by time and folders.