Indeed. He signed no defender of note who came close to being considered a decent signing - even their club captain he brought in was utter gash.
Moyes brought in players for low fees or from obscure locations and they turned out to be gems. Martinez didn't. The stature of the club barely matters with such players - one manager signed Seamus Coleman; the other Gary Caldwell.
Of course the stature of the club matters.
Ability to employ a strong scouting network is vital in signing players like Coleman and there's no way Wigan's would have been anywhere near ours.