It all depends on the airline and the folks that make the lines up, as well as what seniority preferences are...

A lot also depends on the particular domicile, the trip/duty rigs and pilot group demographcs. If the base has a lot of senior people that live in domicile, then standups and daytrips usually go pretty senior, particularly in the summer when kids aren't in school.

ACA/IDE standups typically went senior. This was because standups had good pay rigs that made them worth more money than just the actual block (it was the higher of actual block, scheduled block, or 1/2 duty time for pay... IE if the trip was blocked at 3 hrs roundtrip, but the duty period was 12 hours, a pilot made 6 hrs of pay for a standup).

Another thing to consider though is that day trips can be more of a hassle at times too. For me, if I did day trips, that meant an hour in the car to the airport, 30-40 minutes for employee shuttle and security, fly the trip, 20-30 minutes for employee shuttle and another hour home. 3+ hours of commuting everyday to/from the airport can get very old after a month.