If you go for 35mm tire + guards you'll be able to squize in 40mm tire without mudguards. This would also eliminate or reduce toe overlap. That’s how it works on my touring bike and although riding on 40mm tires is fun I felt like the steering was compromised a bit. For a long tours I run 35mm marathons plus and guards and never had to change a tube.
If you go for 35mm tire + guards you'll be able to squize in 40mm tire without mudguards. This would also eliminate or reduce toe overlap. That’s how it works on my touring bike and although riding on 40mm tires is fun I felt like the steering was compromised a bit. For a long tours I run 35mm marathons plus and guards and never had to change a tube.