Plan B can be in many practice from having income from your jobs, having emergency fund to use just in case, storing your bitcoin in different wallets, then making multiple wallet backups. If you don't have many wallets to store your bitcoin, and only store bitcoins in a single wallet, you can lose all bitcoins in a single accident.
Then a next step is your recommendation, making multiple wallet backups in order to have different options for wallet recovery that is important for your bitcoin fund. The initial wallet can have technical or physical issue anytime, and have other backups to use vital.
Does keeping it in different multiple wallet means storing it in another person smartphone or generating those wallet on the smartphone you are using?, part of the safest way of keeping somebody's Bitcoin is using only one wallet because what storing in different wallet does is that you could easily loss control at any time but if is one your priority will not be much because the only thing you would be putting your heads on is the safety of that single wallet. Instead of the risk of having other people to have different part of your wallet backup the person should instead use another of his phone to import it so that they would have two phones that is controlling it.