About abilities

Today I wanted to start with building an optimal team for online battles. So I searched around the internet for ideas.
I found one very good FAQ about TFFCC at GameFAQs that contains almost everything about the game.
I decided to continue using Cosmos as a healer. Paeon Lv 3, Paeon Lv 2, Soul Voice and Harmonious Force.
But I wondered about one thing: In the description of Paeon it says "low strength" or "full strength".  And what does the strength of this song-type ability depend on?

Because I couldn't find an answer I decided to try it out.
So I used a standard Lv 99 team with Cosmos, giving only Cosmos the ability Paeon Lv 1.
Then I played "One-Winged Angel" in Expert Score. At first I did nothing and waited until the HP were (almost) zero. After that I normally continued the stage. The HP bar became normal again after 198/200 triggers.
After that I did the same with a Lv 1 Cosmos. Result: 201/186/189. (I also changed the amount of HP of the team from try to try.)

Interpretation:
The effectiveness of Paeon has nothing to do with level, stats or HP that are needed to be healed. So boosting up Cosmos makes very little sense to me.

Feel free to post your thoughts!

Paeon heals by time.

I know. And therefore it's the most reliable way to get out of a critical situation during a battle.
Since I didn't switch the song the number of triggers is almost equal to the passed time.
So there has to be a certain amount (e. g. 10% per minute) for all Paeons. And most likely Lv 2 will be double effective and Lv 3 will be triple effective as Lv 1.

Lance skill is also a very good healing skill, i find it more effective than paeon.

There's also skills that reduced damage (can't remember the name) a lot