Yes. Apart from Campbell and Toure, Wenger's defensive recruits have been poor throughout his whole tenure and its no coincidence that their defence has got worse and worse the longer he's been in charge, as the affect of Adams, Bould, Dixon and Keown disappears.
Without their rock solid defence, they would have been no where near the team they were.
I wouldn't be to harsh on wenger re his defensive recruits over the years to be honest. In my opinion, i think the manner and style in which arsenal seem to consistently let in some very soft goals over the years has more to do with the overall attacking style that the team plays. ie. they commit (too) many players forward regularly including defensive players, hence, it makes sense that there will be holes left at the back. Also, they play a very high line (traditionally anyways) with both fullbacks willing to go forward meaning that the centrebacks must be mobile. this means that they typically aren't the tallest, or best aerially. Because if they were (as well as being mobile), they would be truly world class centrebacks a la sol campbell.
also, apart from tony adams, the likes of keown, dixon, winterburn etc were not regulars for england. and only have a handful of caps between them. therefore, if anything, i would credit wenger for turning these guys into multiple title winners. in my opinion, the media has been giving these guys way too much credit. these guys were clearly average, and were made champions by wenger. not the other way round of them giving wenger the platform to succeed as the media so often like to spin it.
some of wengers defensive recruits include; clichy, campbell, toure, vermaelen, lauren, sagna, gallas. as well as defensive midfielders such as; vieira, petit, gilberto silva, alex song (now at Barcelona), flamini (now at Milan). on top of these guys, hes brought through; ashley cole, kieran gibbs. - some of the guys on this list are truly great players, and the rest are still top class players. i dont think its fair to suggest wenger cant spot a good defender personally. its worth noting also that the invincible back four was cole/campbell/toure/lauren. none of whom were originally part of wengers 97/98 first season.
Basically, i would more question wenger's approach to defending rather than his defensive recruits per se. As much as i hate to say it, Wenger has a good eye for spotting a top defender, explaining why he went for sol campbell all those years ago.