at the risk of spinning this thread back to its original question ...
It wasn't merely that there were Jem'Hadar on the planet with our heroes, but critical to the storyline that they and their Vorta Kommissar were already on the planet, and under duress with the Vorta injured and ketricel running out.
That allowed the re-enforcement of the Jem'Hadar's blind obedience and dedication in the most extreme circumstances, as well as their dependence on The White and the consequences of withdrawal. Also demonstrated that the Vorta were rather weak, not only physically but also individually could be self-centered, uncaring for the soldiers under their command (in direct contrast to the anguish Sisko feels), and swayed from their devotion to the Founders.
To me, this episode is rife with contrasts ... The Federation crew's desire for self-preservation while fulfilling their duties vs the Jem'Hadar disregard for their own lives ... Sisko's agony over the suffering of the people under his command and unwillingness to endanger them needlessly vs Keevan's total disregard for his Jem'Hadar ... even how respectful of authority and obedient the Jem'Hadar normally are vs how unhinged they could be when they're unmedicated.