From all the information you provided, PR's, training age, mpw, I would have you do this if you were my athlete...
early season (now): 1600, 1200, 800, 600, 400 @ ~5k pace (2min rest between each - then progress to 1min rest as the weeks go on as well as increasing the pace)
mid-season: 8 x 400m @ 5:20 mile pace (start at 2min rest, progress to 1min rest)
late-season: 4 x 500m @ 5:20 mile pace (first 300 off pace, surge last 200) with 2min rest
The most important thing is that you won't run a faster mile working on 3200 specifics. For faster mile you have to be able to run faster 800m and 400m.
These workouts have helped 2 girls to 5:12 and 5:14 from 5:29 and 5:34 earlier in the year. And for a boy from 5:08 to 4:31.
And no, you're not destined to stink at the 1600.