Schwinn and competitors made a ton of 5 speed derailleur bikes in the bike boom. They had 14-34 freewheels. The same bike with 11-36 on a freehub (and aluminum rims) would be pretty great for a townie.
At the front you want a smaller ring to center that cassette range. You can get other ring sizes for Ashtabula cranks. Probably a 38-42 for normal road going tires on a townie. As for a guard, I’ve found my MTB with a 1x30t front won’t ingest pant cuffs and shoelaces as much as the 22-32-42 did because they’re further from it and there’s no toothy outer ring to snag them in.