First, I'd highly suggest he get his BF% down to 15% or less before starting a cycle. Gear can exacerbate issues in people with too much BF. Is he just trying to "cheat" to lose all that weight? He needs to understand how to diet clean and work hard. Gear is only going to work if he puts in the work.
Now, as far as his cycle is concerned, here's my OPINION:
1) 500mg Test C holds a lot of water weight (it did for me) and at his BF% he may end up looking like those guys out of Westside Barbell (no hate to their work ethic),
2) Masteron is pointless if you're not already lean. That compound is a hardener, used several weeks out from stepping on stage,
3) Primo is used primarily to preserve muscle mass in a severe caloric deficit (like prepping for a show), it's not a cutter and definitely not a strength gainer,
4) For as long as I can remember, I've never gone over 50mg of Winstrol ED, it's hard on the liver and with someone with his BF% I'd highly recommend AGAINST it,
5) 40mcg of Clen could be a great fat burner and this is, so far, the only compound I'd keep in this stack,
6) I'd opt for Aromasin (Exemestane) since when it binds to the estrogen molecule it disables it permanently. With Arimidex, it's a temporary estrogen binder which means after a certain amount of time it will re-release that same estrogen molecule back into the bloodstream. The whole point is to crush excess estro being created by testosterone aromatization.
Once his BF% is down below 15%, I'd go for a 12-16 weeks "cutting" cycle that looks something like this:
1) 400mg Test E per week (holds a bit less water than Cyp)
2) 200mg Tren E per week (less goes a long way while minimizing it's side effects)
3) 500mg EQ per week (to preserve + gain quality lean muscle with low side effects)
4) 40mcg Clen (great to take before fasted morning cardio for expedited fat loss)
5) 25mg Aromasin daily or EOD (depending on your blood work)
Going off #5 above, I'd also highly recommend he gets his blood work done every month to monitor lipids, liver, estro, hematocrit levels, etc. It's MISSION CRITICAL that he does this. I cannot stress this enough.