In the game, and in the lore, there was a council which decided how spells should be named and they decided on Fire 1, Fire 2, Fire 3, and so on...

As FFXIV has evolved, spell names looked to communicate if they were ether AOE or Single Target, but as it is now, it's not clear if a skill is an AOE or single target ability.

Case in Point.

Fire 1, 3, 4 = Single Target
Fire 2 = Multi Target

Thunder, Thunder 3 = Single Target
Thunder 2, Thunder 4 = Multi Target

The same is true for other jobs outside of BLM.

What I hope we will see one day in this game is that Single Target Abilities keep with the 1, 2, 3... naming convention. And AOE abilities are appended with "aga"...

For example.
Fire 1, 2, 3 = Single Target
Firaga 1, Firaga 2 = Multi Target

Spells can still level up in numbers.

Thanks for your time an attention.