We've discussed this before--and we worked out some playable chords here:Previous Wichita Lineman Chord discussion

You can get the chord progression to work if you play one count for the chord symbol and one for each consecutive slash mark.

Jimmy Webb liked his chord progressions to move in unusual ways, so you'll do best by counting and playing simple downstrokes, and resigning yourself to the fact that there are no "easy" chords to this tune--

If I were to change anything, I'd start out the song with an F11 chord(1-3-1-3-1-1) instead of the Gm7. I haven't listen to the record lately, so I don't know if it fits with what is played, but it sounds better to my ear.

Even though Jimmy Webb wrote a lot of really big hits, they didn't get covered a lot by bar and club bands, because the peculiar chordings made it difficult to work them out by ear, as was the custom in those days.