Can any team comp clear?

[Zerathor]

I think that is correct for a particular combination. However, I believe your math requires that jobs are allowed to repeat which means it allows for groups like NIN/NIN/NIN/NIN or DNC/DNC/DNC/DNC to form which just isn't realistic. A lot of PFs enforce no dupes for difficult content (Savage, EX, etc). So for calculating permutations you might want to say that a job cannot repeat once selected. If we do that I think the number of permutations becomes 35 and thus the odds become 1/35 for any particular, randomly formed combination.

10 dps jobs, 4 total dps

10!/[4!(10-4)!]

This accounts for duplicates. 210 dps combinations of unique dps jobs

a small percentage for a Personal DPS job to not get a party if it happens.

not an argument.