But Memory Alpha is just bullshitting its way through the ranks without any sort of evidence. All that was ever said was that Colonel Day was a Colonel, and Colonel Kira was a Colonel, and all that was ever shown was that they wore different pins. Colonel Kira also wore the three pins of a Starfleet Commander, making her the likelier candidate for Lieutenant Colonel than Day.
Of course, it might be that there are other sorts of Colonel in the Bajoran militia, to confuse the issue. But I don't see why we should dream up such fictional ranks when the system so far seems to correspond to the familiar US Army system exactly. Memory Alpha has some sort of a crazy fixation about a Bajoran rank they call "Field Colonel". It's completely baseless - it's not part of the episode dialogue, and has no proper real-world equivalent. But in theory, alien militaries might have alien ranks. In which case one wonders why anybody would even try to pretend that those ranks could be translated into English and shoehorned into the US Army or Navy systems with a few dangling ends.