My husband and sons have the same issue. My husband tried growing out his hair in high school and had legit poufs from the curl and coarseness. It sounds like his hair needs moisture and a barber that knows how to cut coarse/curly hair. 

The oiliness of his hair and scalp is most likely caused by dryness. His scalp overcompensates for the dryness on his scalp. The products we have had the most success with is Briogeo Scalp Revival Scalp Therapy Essentials Value Set.  They use the micro-exfoliating shampoo two-three times a week. 

For daily shampoo and conditioning, we use Bumble and bumble Hairdresser's Invisible Oil Shampoo 33.8 oz / 1000 mL and Bumble and bumble Hairdresser's Invisible Oil Conditioner.  I know using something with oil in the title sounds counter productive but it has worked wonders. 

For styling, they use Moroccanoil Curl Defining Cream. It gives them curl definition and control without it being crunchy.

Finally, we all sleep with silk pillow cases. It makes such a huge difference, especially for my boys because they end up with funky frizzy spots when they wake up that no amount of water will flatten or fix.

Hope this helps!