The easiest way to tell if you need a "makeup" track is to google the switch and see if any are included with the switch. The O31 switch comes with a makeup curve, the O60 and O72 switches come with 2 half roadbed tracks and 1 no roadbed track and the O36 and O48 don't come with any.
If you look at the photo, you can see that both tracks in the example have full roadbeds. If you try to attach the red track, you can see that the roadbeds will hit with each other. This is because the diverging tracks are too short. I'm not sure why Lionel chose not to make full switches. However, if your design requires it, any track can technically be attached if you first cut away some of its roadbed. SCARM will let you attach any track while RR-Track and AnyRail both require a makeup track. Unfortunately, while that avoids mistakes for those who don't want to cut their tracks, it also limits design opportunities for those who will.
The other thing is that if you don't add the makeup tracks, it may be harder to connect things, especially things like reversing loops.
This photo shows your setup. You can see that while the switches can be connected, you won't be able to add another track without cutting the roadbed.
