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It's a bit vague, stem hardly affect how the bike ride, just the feel of it.
Top tube length can be a hit or miss, depending on the seat tube angle, so it might actually fit identical despite a longer top tube.
Lastly, stem length varies by handlebar reach, says 90mm reach handle and 80mm stem or 70mm reach handlebar and 100mm stem, it's likely the tourer/audaxers have classic handlebar that's extremely long due to the old style brakes levers being a lots smaller, that fitting modern levers extend the reach a lots.
Personally, the fit should be closer to road but a less aggressive position (slightly more upright).
I have a question on tour/randonneur geos: should your frame have the same toptube as for example your roady? Or shorter/longer? I see some pictures of tourers with short stems (80mm it seems), is this a thing?
I'm asking because I'm eyeing a lovely frame that has a toptube which is 2cm longer than my roady (but with the same seattube). Would this frame with a 80mm stem work or will that be rubbish? I really want the frame, so maybe I'm being unrealistically naive/blind.