Doing coinjoins in step 2 is simpler and more private. When you do onchain vs LN swap, swap provider can correlate onchain TXO with LN node pubkey. Which means you need to do more than one LN wallet, adding extra hops there, where, again, coinjoin is simpler. Basically, you are trying to avoid coinjoins at all costs, even if it means spending more time and effort. That doesn't seem rational to me, but your choice!