We are here. Well not "here" but wherever we are, we are there. Me? I'm in the Interdimensional Rift as it is one of my favourite final dungeons in the Final Fantasy series.
This is my favourite 2-D Final Fantasy and is probably my 5th or 6th favourite Final Fantasy. My top 6 are all very close, almost touching each other on the scale; so while it is in 5th or 6th place it is in the top tier for me.
First off, it is unwise to ever correlate the amount of character to how good the game is. I'm not saying that you do but to those who do - they are stupid. The characters in Final Fantasy V are developed, have their emotional moments, and their bonding, compared to Final Fantasy VI which has the most characters in the entire series (by characters I mean those who are in the party, if what you meant otherwise let me know). Final Fantasy VI has fourteen characters, two of which are optional but 6 or 7 out of the 14 or well developed while the rest get some development but not on the same level and some don't get any at all. Final Fantasy V may not have a huge party but those characters have their own personality, background, and are developed through the story.