It had been a long time since Adam was a rookie, though it wasn't so clear-cut in his case. If he was interested, and he looked into the statistics with Silvana's help, he would find that he was not only completing fewer missions on average than the other Phantoms, but he was completing almost no missions at all compared to the others.
Barring the missions he needed to evolve further, as in the case of Brass Puppet to unlock his Lock, Adam didn't even complete ten missions in his entire time, even though he was already a K2-Phantom.
In fact, most K0-Phantoms who were less than three months on this path completed more missions than Adam.
It seemed like a poor result, but the military and the Citadel government were well aware that there was no point in looking only at quantity - sometimes quality was much more important.