Bingo! Theres a reason why goink always posts pix of himself in a tank. All arms and shoulders. Shareif called hinm out of this.

At 5'8" I was 185 at my heaviest, now I'm down to 150 with probably more muscle than I had then and I'm still not stage ready. However, at 185 I could still see all my abs when flexed. If you can't see abs at all then you probably have a larger percentage of your much heavier bodyweight to lose.
Your assessment of 190 lean does not seem entirely unreasonable for a 6'0" tall BBer. I would guess you could do that if you have very good genetics for retaining muscle on a caloric deficit. If not you might end up closer to 170-180. Whoever said you need to lose 20lbs is not making any sense unless they just mean to have sharper facial features and a trimmer waistline.
I think you should diet down. You will still have big arms, but more importantly you will live longer, and be able to keep a BBing look for many more years. You are getting to the age where you are too old to be overweight without health consequences. I mean no disrespect when I call you overweight. Clearly you workout and carry a much higher percentage of muscle than most of the fatties in this overfed country. Here's the thing though, your body especially your heart, does not like to be 250lbs even if there is a shitload of muscle.