Be glad you have an ER to go to. Our local ER closed down because of the costs associated with running a small rural hospital. So what once was a 1-20 minute ride to ER is now 1-1.5 hours....
Personally I would just stick with the current 23.1-34 rear tires. I don't row crop anything so wider is better for me. So if anything I would be swapping from a 20.8 to a 23.1.
You need to compare/measure the rolling circumference of your tires to the specs of new tires. Rolling circumference is the number you need to look at.
Just a quick glance and a 20.8-38 ranges from 213" to 218".
A 23.1-34 ranges from 209" to 213"
And 18.4r38 for 201" to 208".
None match up...
No wedding ring for me. As a farmer/mechanic/welder my hands are in a lot of hazardous places. My fingers are valuable so I don't want any extra risk to them.
I push the majority of my T-posts in with the bottom of the skid steer forks.
But for the occasional random post I still use the finger smasher 9000. Got a few scars on my hands.
Clover in my pastures is great.
Clover in my hay fields is miserable. Around here by the time the Clover is dry enough to bale the grass and trefoil in the field is so dry it disintegrates into a cloud of dust out the back of the baler.