Smith runs hard, and has size, I thought he looked pretty interesting in preseason. If he were to show well he'd very possibly be scooped by another team if waived to put him back on the PS. That would suck b/c he looks to be a solid developmental RB.
Simon was drafted in 2013 but was PUP'd that season, played in 10 games in 2014, starting in 5, then was available in just 1 game this season. He has some legit ability and excellent size, but all the talent in the world won't cut it if you can't stay healthy. His cap cost is close to $585 K., rookie contract. He's had foot (toe) and ankle problems all his pro career and is regularly on the injury report. At this point, by the end of this his 3rd season on the team, he will have been available to play 11 of 48 games. He will need to positively demonstrate he can stay healthy for him to make or stay on the team going forward. For him it is likely a close decision on what to do with him waive, or IR. Pete and John are sometimes loyal to a fault but I could see them moving on from Simon if he can't stay healthy.