For a player to get a feel for the syncopation of repeating a three note phrase over common or cut time it's necessary to repeat the basic pattern until it's 1. become muscle memory 2. the ear can track where the one is at all times.
The second part is the hardest.
Set the metronome to 80 or slower, and play Ex.1 non stop. After a while it's going to be hard to figure out where the "One" is in 4/4 time. Feel which right hand digit is playing the downbeat, even accent that note if it helps. Trying to silently count to four to yourself while doing this at the same time can help find some balance in a lopsided sounding pattern.
Repeat the same process for Ex.2. I find my right hand and forearm tense up on this one and it might be because I have a tendency to bend my hand back toward my forearm, but so does Canadas greatest tele picker Steve Piticco!
Ex.3 combines the forward and reverse rolls. Once you feel comfortable with the first two examples give this one a try with the metronome.
Ex.4 is the same forward roll with one small change, a technique called "double thumb". Use two downstrokes in a row followed by the middle finger sounding the highest string. It takes a little getting used to but after a while it feels a little more comfortable than using the m and a fingers together. It worked for Danny Gatton and it's still working for Johnny Hiland.