LF: Tidus (eventually on his way out)
RF: Larbeight
MF: Brother (may eventually be benched)
LD: Tatts (soon to be gone)
RD: Naida (soon to be gone)
GL: Nimrook

*all characters around lv60 and up except for Nimrook

All-around speed used to be my sole strategy, but now I've been enlightened to some players with more potential.

This will be my lv99 team when I get there:

LF: Larbeight (arguably the best shooter in the game)
RF: Linna (max. SHT 92, low END, but high PAS)
MF: Mifurey (starts out really slow but ends up pretty fast; comes equipped with Tackle Slip 2)
LD: Auda Guado (unlike other Guado, his ATK & END bulk up good enough for me)
RD: Nav Guado (see Auda Guado)
GL: Nimrook (edit: forgot goalie)

I used to use sole speed. Now I see that speed is only important in the back. The front should be reserved for big shooters (and no, Tidus doesn't qualify- max. SHT 78-ish, can't remember). High ATK & BLK all around for this team, which will give me a tremendous defensive boost.