Structure of Titus 2

Reading Titus 2 with someone this morning we noticed the following concentric structure:

2 Older Men
         3 Older Women
         4-5 Younger Women
 6 Younger Men 

It is noteworthy that while the older women are to mentor the younger women, there is no corresponding expectation for the older men toward the younger men. Perhaps this explains the concentric structure.

Furthermore, it's also interesting to see the concentric structure in the commands to the older women (2:3), with two positive commands framing two negative commands:

do live reverently
        don't be slanderers
        don't be drunkards
do teach what is good

Perhaps Paul is encouraging the "sandwich technique" of giving feedback to these women, modelling to Titus how to teach older women from his position as a younger man.