That's not true.
FCD can be used from anywhere. It is a "summoning technique". The user is able to summon a toad directly above the target.
Offensive; Close, Medium, Long ranges; Rank: B
A destructive dive that takes full advantage of a giant Toad's bodily mass! The strength of the fall varies depending on the caster. In the case of someone like Jiraiya from the Sannin, the summon can be performed in an instant right above the target, further adding the great gravitational force of a good several hundred meters high dive to the Toad's own weight!!
How does the summoner get several hundred meters above someone -__-
Also notice the ranges, it's an all range jutsu. The user can summon a toad from afar directly above the target they aim it for. It's a B rank jutsu for a reason, it's not simply a regular summoning jutsu. How do you think Minato summoned Bunta from the Hokage stone faces, all the way from that distance from where Kurama was, on the other side of the village.
The jutsu wouldn't be all ranges, if it required the user to be directly above the target. It's also an extremely fast and hard to evade technique. Not only because of the speed, but because of the giant toad mass making it difficult to escape.