Afraid it wouldn’t work as well. If you cut out with the wide part of the tumbler on the fold, instead of piecing the pairs, then you would have to sew and pivot too much where it goes in and out to sew rows together that way.
The way I did it was straight line sewing. You sew row’s together, from top to bottom. Half a pair at time. You have to lay all the tumblers out first and keep them in order. I did however have my fabric doubled, to cut more than one at a time.
I drew the template and hubby cut it out of scrap plexiglass. A friend that had a small tumbler gave me measurements