I think that, in most cases, you're probably correct with regards to the maximum range of a repeater being more than the 'theoretical' maximum range of DMR. Consistently, when MOTOTRBO systems are designed properly, they have had more range than wideband analog, and of course narrowband analog, too, with all other factors being equal (same antenna systems, power levels, etc.).
When I hear of someone having less range with DMR (MOTOTRBO) than with analog FM (wide or narrow), I think there's something 'odd' going on with the system - either a problem in the design of the system, a problem with the equipment, or possibly some kind of interference that is more noticeable with a TDMA digital signal than with an analog signal.
As to TDMA vs. FDMA, with respect to range, that's a bit like comparing apples to oranges. The way forward error correction is handled, the type of modulation used, as well as specifics of the receiver and transmitter design, are going to have a large bearing on how they compare with each other in terms of range. So other than just comparing two specific brands/models of radios/systems, it's going to be hard to get a 'real world' comparison of the two and be 'fair' to both.
With everything equal, though, that is an interesting thought, if considered from a 'theoretical' standpoint.. I'll have to bounce this off of an RF engineer that I know and see what he thinks. His speciality is in RF propagation analysis and modeling.
John Rayfield, Jr. CETma
At some distance, the incoming signal will be delayed enough to step into the adjacent timeslot.
Whether this distance is within the operational range of the repeater is not known.
There is room within the GSM timeslot for 35kms of distance. I don't know if anybody has calculated the maximum distance for p25 or DMR based on the timeslot size and the size of the packet.
Since it's never been stated, we can probably assume that the room within the timeslot is sufficient to allow use out to the maximum range of the repeater.