It's funny that you're asking about TG, as SMF wildstrike hits harder than tg's with the 35% offhand dmg boost^^. As i said, it's highly gear dependent, but for bis gear they are definitly close.
About the gaining rage thingy.
Yeah, i think you are mistaken there. You somehow think, if you save rage in CS you have more rage to spend in general, but thats just not true.
I think you agree that our overall ragepool for a fight doesn't change by the usage of shockwave, as it does not generate or cost any rage.
Yes that's right, that's why we do not lose rage by using shockwave, but we are still not gaining any additional rage, we're just spending it at some less beneficial point. You are somehow thinking that you gain rage by doing something without a rage cost during a gcd. Thats not the case. It's just like you do not actually gain more rage by waiting 1 GCD. The ragebar fills because you are just not spending any.If you save out 30 rage on a ws or 10 rage on an RB or procced WS by using shockwave during the CS window you will still be able to utilise this rage after the CS ends.
So obviously we will spend the rage we save during CS somewhere outside of CS, but that doesn't mean we spend more rage, just the same amount of rage at a different time or with different abilities.
Just to make the point how much the better cooldown stacking influences dragonroar exactly clear. The cooldown stacking on DR will make this ability about 70-100% better than used without cd stacking, throughout the whole fight. That Bloodbath, Synapse Springs and DR all lie on 1 min cd and the others are off the gcd, is just godlike. You have to think DR always triggers 30% extra dmg on bloodbath, gets full benefit of 1920 strength of synapse strings, gets nearly always the 3000 strength procc of relic of xuen (55 icd, proccs aprox every 60sec!), in a 6min fight benefit of 1/3 strength pot. (with prepot) and 1/3 guaranteed Skullbanner dmg boost. All of these effect SW just for 1/3rd. Also your meta socket is a guaranteed 3% dmg bost on DR.
30% dmg bloodbath, 10% dmg from crit boost, 6255 additional average bonus strength for DR in current gear. (at 44k attackpower bis geared raidbuffed, 6255 str should be roughly a 35% attackpower gain).
For SW you got: 10% dmg bloodbath, 3,3% / ~35% critchance(w. avg reck) => ~1% crit dmg boost, 2085 additional average strength (15% ap), and a 7% extra crit with unglyphed reck t14 2pc.
So instead of ~93% dmg boost , we are looking at about ~37% dmg boost on SW. So without consideration of cooldowns, SW needs to do significantly more damage than DR to be worth using. (This is just a rough estimate from the above and the % is not entirely correct, but for the sake of the argument it's sufficient.)
edit:
@reptiel
i just checked your armory and i really don't see the reason why your shockwave does so significantly more damage than your wildstrike. Yes your gear is ~20 ilvl above your weapons that significant and shockwave should do more damage than ws at it scales better with attackpower but not with weapon dps. But 50% seems way to much even raidbuffed. Also your raging blow mainhand hit should be close behind shockwave, but way better if you add the raging blow offhand hit. Did you forget that?
I tested it for myself on life and WS/SW are pretty close for me, during enrage + colossus and without, though WS has a wide dmg gap (min to max) and shockwave does always the same amount. RB mainhand + offhand is way better than sw for me.