I would throw in the 257 AI in the mix too. The 6/284 eats barrels but for some reason the 25/284 less so, but then the 6.5/284 loses target accuracy pretty quick. Maybe it is because the 25s are mostly hunting rifles so 2-2,500 rounds is acceptable. It is odd this isn't an issue with the 25-06 with the sloping shoulder although the longer neck could compensate for this.
Then there is the 25 Creedmore which duplicates the Roberts but has better brass available for it, it could also go in a short action. The Roberts can fit a short action but most are built on a long action, same for the 25/284 almost all are on a long action.
Either would be good and the two would make a nice mismatched pair. I think I would do the Bob and in a long action a 25-06. The 25/284 makes sense in one of the medium actions like the NULA and some others. If a long action then I like easy with the 25-06. Some would say the 25/284 is more accurate or at least it has the design features that are thought to make an accurate cartridge but I don't know if you could demonstrate this with hunting rifles.
Whichever you go with I would twist it as fast as 1-7" so you could shoot the longer Black Jack and Hammer bullets.
