I don't consider paying a backup running back $3 million a season a modest contract. That doesn't mean Starks isn't a significant upgrade over an undrafted rookie like Don Jackson.
Well, using $3 mil equates to a 1 year contract: $2.25 in cap for this season and $750,000 in dead cap for next season assuming he's released after this season.
Given that Lacy would never be considered a 300 carry back even under the most optimistic scenario, the backup is assumed to get a lot work. Here you have a vet with years in the system coming off a very productive year who can run some, catch some, block some. That price is hardly out of bounds.
I would have liked the Packers to have drafted and carried a 3rd. back. I had Ajayi in the third round for the Packers in the 2015 draft, low enough to compensate for injury risk, an injury he played with in his last year of college when he gained over 2,500 yds. from scrimmage. I believe at the time your opinion was he'd not last that long; they could have had him in the fourth round or even a trade down into the upper 5th.
But that was water under the bridge when they signed Starks to his deal which, considering all the factors, was hardly out of bounds.
The best argument against the Starks deal was his history of knee sprains; on the other hand he got through 2015 clean which was an understandable decisive factor in giving him that deal.