A 6'11" SF. Boy, that would be amazing.
For comparison, some of the other SFs in the league are James (6'8), Durant (6'9), Porter (6'8), Tatum (6'8). The closest comp I can think of would be Odom (6'10). During that period, teams used to worry about their length with Odom, Pau, and Bynum. Of course it takes lot more than just length, but sounds so juicy.
As to strength, let's see. He is listed at 240 lb, which is the same as Durant. Seems to be carrying no fat, which should suggest lot of muscle and strength. How he manages in real game situation, we can only speculate.
That said, I doubt this can be a long term solution. He needs to improve his outside shot to begin with. However, it might work in short bursts, particularly when the opposing team has a big SF (KD).