Is it considered a dps upgrade if, for instance on garrosh, to use storm earth and fire on the adds before spinning crane kicking, tiger palming and RSK beforehand obviously?
Uhm, I believe I tested the clones in 5.3 and it seemed, that they don't do more dmg because YOU have the Tiger Palm Buff. You have to Tiger Palm once after you summoned your clones and after they are on their target(not still midair jumping to the target). They need to copy the Tiger Palm to get their OWN buff - then they do get the Tiger Palm benefit.
Unless they changed it in 5.4 .. I got some testing to do.
Maximizing your SEF-usage grants very good damage. But you have to bear in mind when it's worth it to summon your clone and when not. If my above written text is still true, you have to concider a little dps loss at first. Clone does no dmg while jumping to the target and does less dmg while their own TP buff is not up. But in the longer run it will pay off.
PS: I still wish the targets attacked by a clone would get some kind of buff so you can track which targets are attacked by clones and don't sacrifice damage while accidentally attacking the same target.