The two tags hd-wallet and deterministic appear to be encompassing the same scope. Does it make sense to keep both, or should they be merged? If they are different, how?
They're describing different things. Deterministic wallets derive all keys from a seed. Hierarchical deterministic wallets derive subkeys from a seed, and generate subkeys from those. That allows you to share part of a wallet with someone else, which isn't possible with deterministic wallets.
All hd-wallet questions are deterministic questions, but not all deterministic questions are hd-wallet questions.