It wouldn't be the worst thing in the world to have 2 quality RBs, the whole discussion reminds me of the start of last years Red Sox season "What are we going to do with 6 quality starting pitchers?"
1) Watson and Graham is a good comparison. Watson was drafted with the second pick in round 1, having the luxury pick made Watson a viable option at 32 even though he wasn't even the highest rated TE (Troupe was I believe). Graham was a young starter with potential (much like Maroney) he also couldn't stay on the field (much like Maroney).
2) The money is cheap, Maroney signed a
5 year 8.75 million dollar contract , less than $2M per season.
At this point Maroney has not proven he can handle the NFL load, if you hit the jackpot and they both can play then the team has a very high class problem of getting them touches. The exact opposite of last season when at the end of the year Heath Evans was the only option at RB because everyone was else was banged up.
...Contract details....
Maroney signed a five-year deal worth a total of $8.735 million in August, 2006, according to the NFLPA. $6.13 million of the contract is guaranteed. Easily-obtained incentives could increase that amount to $6.2 million.