In sensus plenior, by way of drash, all the brides in all the stories are one bride. Here the one bride is represented by five who have oil and five who do not.
Numbers in sensus plenior are not the same as they are in popular typology.
5 is the number of man, 10 being two fives is the dual-natured man.
The bride is the church. We have the nature which is wrapped up in buying and selling with merchants. This is the flesh. We have the nature which is filled with the spirit (oil). The old nature will perish.
This same theme is represented by a long string of women:
Rebeckah was a virgin, but in the language of riddles (without imputing any sin) it says that the servant 'took' (same word as 'married') her, and she was uncovered until she saw Isaac.
Leah and Rachel play the two parts as Leah sneaked into Jacobs wedding bed.
Gomer was a prostitute, yet she named her first son "God sows" as a hint of the virgin birth.
Even 'Mary' means rebellious, yet she was the virgin mother of Christ.
Tamar played a harlot, but was called 'more honorable' than Judah.
Rahab was a harlot, but became the mother of the promise.
The ten virgins are the same theme. Half represent the pure bride of Christ, the other represent the 'old nature' which buys and sells with the merchants.