Self-buffing macro

Hello, I came back to enjoy this game after few years of break, and having rough time remembering exactly how macros work.
Problem I'm trying to solve: rebufing myself while leveling, putting on Seal and Blessing... Could it be done by one button?
I was trying something like this with no success: "/castsequence reset=60 Blessing of Might, Seal of Command". It only works if I click button 2 times. Is it possible to get both buffs via 1 click there?

Nope. Because each of them cause GCD (global cool down). If not, some classes with instant skills and no CD on them could abuse it and make "nuke" macro or weave lots of different effects in one attack

I see, thanks for clarifying this :)