Two things to think about here are:
1) “Native” versus “Assisted” fly first pitch
Most freestanding tents will tell you that they can pitch fly first, but it’s not a ‘native’ or easy thing to do so in the sense that you can’t just pop the poles into the fly and be done with it. Instead, you need additional components like a groundsheet or staking out the pole positions etc. It’s more hassle and harder to remember how to do it, so in bad weather you still default to the regular method.
Most freestanding tents are hexagon shaped but the poles only go to the 4 corners, so there is not straight line of material between all the pole positions. It’s the inner that prevents the poles from popping outwards, so if you pitch just the fly and poles the hexagon deforms into a rectangle and it doesn’t work without a groundsheet which you have to buy, carry, and remember how to use and even then it can have rain puddles on it by the time the fly is up. Ideally a tent would have the poles go to all the same corners as the fly does, so that the poles can define the fly shape without additional stakes or groundsheets needed.
2) One piece setup vs inner only
Normally you have to choose between a tent that will set up as one piece or can set up inner only. If the poles are on the outside of the fly you can clip the inner to the fly and set it up as one piece (e.g. Hilleberg) but then often (but not always) you can’t pitch just the inner which is a nice option to have. If the poles are between the fly and inner, then you can pitch fly only or inner only, but probably not both together. So it tends to be a choice whether you want a tent that can do a combined pitch or an inner only pitch because you rarely can have both.
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