It would be too soon if i never hear the term 'deca-dick' again - especially when referring to only DHT (or replacement of DHT with DHN).
200mg of T will of course provide plenty of DHT. That much is true, however as for preventing 'deca-dick' - not in my experience.
87.5mg of nandrolone a week is a terrible dose - really really bad idea. Full suppression, minimum results.
From what i have read about the issue (i have not experienced it myself), the effect Stan is supposed to have on joints is not due to a 'drying' out as you suggested (although a distinct drop in estrogen could cause this i expect), but due to the strengthening of connective tissues becoming brittle - over time of course.
Nandrolone being pro-collagen would assist this i would expect however, as will a dose of 200mg or under of T.
I would look more for:
If you keep calories low/moderate and protein very high you will experience a significant body re-composition effect with little scale weight increase (although i would expect some of course).
I am assuming that as your name is GI Joe Galway - you are talking about actual football and not American Football?
Nandrolone is not particularly susceptible to raw mass and bulk like T is, with the results being much leaner and visibly more muscular than T is - which allows a higher gain of fat and water (due to the aromatisation no doubt). However IME the anabolism far exceed that ofdrugs like masteron or Eq - common 'replacements' for nand.
Nandrolone is a pain in the arse, it does cause additional inhibition and sexual dysfunction in so many, but IME it is really quite irreplaceable dose for dose.
Recently I have found that 700mg Drostanolone a week is similar in muscular effect to 200mg of Nandrolone (but of course is significantly more androgenic).