ShiKage's Big Bang Paladin Build

That's no way to build. Say for instance you are at a boss spamming Dispel, relying on Combat Orders will be more or less make you weaker as will your skills you are trying to use between Dispels and rebuffing. This same instance was the problem for people trying to rely on Maple Warrior to use certain gear when they were stat-less or low-stat. Again, this is a very wreckless way to build that will not benefit you in the long run.

What I'm trying to say is this.

Skills that look nice on paper almost always aren't the case in real usage and real scenarios. Ground Smash looks nice on paper. It sounds like a nice skill to have that's strong and dependable, but really does it effectively fit into a skill set for the 2nd Job that doesn't focus on going multi-monster attack constantly? True skill is knowing what is better suited to situations and changing as needed to adapt to the situation, not just having a one shot cure-all that focuses on the generic only.

Ground Smash does not replace Power Strike with Fundamentals and Final Attack effectively if you use it correctly. In fact as shown earlier Power Strike is stronger and is more suited for early bosses and PQs. Slash Blast is weaker but again Final Attack does present a possibility of extra damage on more mobs when used correctly and still hits more monsters at once.

Ground Smash does not combine with Final Attack for added damage meaning you'll always get that 300% damage ratio of your range. Even if Final Attack isn't an absolute it's a chance at extra damage per attack. While it may have limited range of effectiveness, you again have to think about it, what if you are in the right place when it activates and hits? That's 380% from Power Strike with Fundamentals + an extra 150% damage at random for more damage. Now add in 250% with an extra 150% possibility from Slash Blast with Fundamentals and Final Attack. That's 400% total damage at chance on up to 6 monsters total.

Now add in this... Final Attack will automatically attack. Even if Ground Smash does strike at weapon speed, it will not get an automatic 2nd attack.

Power Strike has a good probability of getting at best 530% total damage to a single monster.
Slash Blast has a good probability of getting at best 400% damage on up to 6 monsters of total.
Ground Smash has the set damage of 300% on 3 monsters only.

Regardless of range, power, etc. Ground Smash does not stand up if you know how to fight and know how to use your skills effectively and wisely.

Even if you're at a boss with Dispel, you will always need cast Combat Orders first, otherwise you will be weaker. I don't see how this is relevant at all.

Ground Smash does activate Final Attack. Slash Blast cannot do 400% on six monsters. The most damage it can do to one monster is 350%.