Yup, it should generally be pretty reliable if the lead loco can't pull the whole train, and the pusher can't push the whole train, either. That way should reduce the chances of the lead loco pulling too hard and stringlining the thing, or the pushed pushing too hard and shoving the cars off.
I tried this out today. In summary, as Randy and others noted, the key seems to be to ensure the locos at each end do not handle all the work.
I used my 3 Geeps. They are a P2K GP30 and a Genesis GP9 in the lead, with a Kato GP35 pushing. All have LokSound Select decoders and are speed matched reasonably well with CVs 2, 5 & 6. All were controlled together in a common consist; i.e., using one throttle.
This was mostly for fun as my roughly 5' x 9' layout hardly needs long trains. I started with 22 cars but increased it to 31 cars. It was interesting to observe the couplers on the flat, uphill and downhill. One thing is to recognize what the Kadees do as we run trains, doing the job well whether in tension or compression. I only ran up to moderate speeds but tried all the mainline routes enough to feel derailments can be avoided.
- The most stressful occasions I observed were some quick starts, jumping the throttle from 0 to 10 or more (of 126). If the rear loco moved soonest, this briefly caused the rear loco to push the train quickly into compression. Perhaps this happens because the locos behave a bit differently. I have not turned off the BEMF and have not run the CV54 BEMF "training" for these locos. (I will do that). A contributing factor was that the lead locos and some cars were already on the hill whereas the pusher and cars near it wer still on the flat, easier for the pusher to get going.
- I was most nervous about light cars being pushed into derailment than about being stringlined under train tension. I added two rather light hoppers (about 60% of NMRA recommendation), first separated somewhat and then together in the middle of the train. They seemed to behave. I think that such (light) cars would be the biggest weakness, perhaps the worst case being light cars with poor adjustment of the trucks.
Oh, and if one has mainline permanent magnetic couplers (I have the 3-pair vertical magnets) this will doubtless increase the odds of undesired uncoupling at certain speeds as the couplers tension varies somewhat from steady state in the train.
Just another wrinkle of fun with the hobby. I look forward to showing the grandkids. In this case it was fun to hear the front loco sounds, 4 Soundcars in the train, plus the pusher loco working.