What do you think about this setup?
I would not use any ledger devices, they can literally block your transactions with their sanction compliance crap.
All their devices are closed source, most likely have a hidden backdoor, and ledger S is discontinued device.
I would not use Tangem wallet, that is also closed source, and they leaked keys over their mobile app, that is not acceptable.
Trezor is OK, but I would wait for the end of the year when they release new Trezor device.
Would it make sense to combine these different wallets for better safety, or is it overkill?
I would choose open source and if possible airgapped device.
As backup I would choose Satochip Seedkeeper cards, that is better option than using pen and paper backup.
I think "seedless" is reckless.
Proven reckless and unsafe, as people lost money using Tangem.
I am just waiting for next big ''bug'' from them 