I'm the first to admit that the AI has it's merits, but orchestrating an elaborately unballanced situation doesn't prove they're good.
Anyway, this challenge really is impossible. Take off the handicap and I can do it--****, I've done it before lots of times. Before I started playing competitively (actually playing other really skilled players, instead of just friends that would come over and play for hours on end), I got my practice playing against the computer. I started by playing level 9 AI's until I could consistantly beat them. Then I added a second, and then a third (still FFA). Then I played against two level 7's with TA on, progressing slowly until I was fighting two level 9's. Take of TA and it gets harder still. Now I can beat two lvl 9's without team attack about 90% of the time. 3 level 9's is significantly more difficult, but I get lucky every once in a while and do it. Of course, if this was just a "beat the challenge" sort of a thing to you, you could make them all jigglypuff and just use roy's backwards up-b trick, but that sort of defeats the point, doesn't it?
These don't do a whole lot of good for playing against real people, but it does help as far as mastery of your own technical skills are concerned, and there is one practical purpose. If you play a lot of TA off games (2 on 2 tournies?) these sort of matches are great practice for when your partner dies and you are left alone. They teach you an effective evasive strategy; to run away and poke but to quickly switch to offence when there's an opening for attack.
