I've never played Final Fantasy 8 before, but I heard from a friend that monster's levels are based on Squall's level. He said he kept Squall dead the whole time and wailed on everything with the other two part members he had. I'm not sure how reliable this is, considering I haven't seen it myself, but it's worth a shot.

Monster levels are actually based on the average level of your current group.

So with squall dead the whole time and your other two members at level 100, the monsters are going to be about level 75-76. Which still makes them considerably easier than normal--but the difference in strength is no where near as vast as my method.

Triple Triad

For anyone who is interested in playing it against real people.