Ahkello is a boom/bust type of FA signing. He brings experience, size, and speed to CB. Obviously, they are looking at him as a RCB moving Durant to LCB. With Tomlinson as SCB. God knows I'd rather see Witherspoon out there than Kendrick no matter how much Morris likes him. His play is inconsistent which is why he hasn't stuck with any team. He's got the athleticism, speed, and size of a good starting CB but between his nagging hamstring injuries and battered confidence, his play has never maintained a high level of consistency.
He was drafted by the Niners in the third round but he had the length, speed, and athleticism of a much better player than his draft position reflected. Most evaluators dropped him into the late second to the middle of the third round for one reason. He lacked polish and was looked upon as a one year developmental type player. But SF put him out there as a rookie starter and those technique flaws surfaced. Then there were the nagging hamstring injuries. Those combined to put him into the coaching doghouse, much like Morris has done with Rochell. The Steelers saw improvement in his overall play but it was his lack of availability that got him released, much like Terrell Lewis here in LA.
If he can stay healthy for the first time in his career and polish up his game in LA he could be a legit starter for 2 or maybe 3 years or otherwise, he's a one year rental at best.