You don't get it? 4 time DPOY (tied with Mutombo for most all-time), 4 time all-star, 3 time All-NBA second team, two time third All-NBA third team, 5 time All-Defensive first team, 1 time All-Defensive second team. And of course NBA champion (nearly twice, taking the Spurs to 7-games). For at least 6 years, he was massive impact-player.
Wallace didn't start young, either. Wallace was 22 before he touched an NBA court. He was 24 before he started playing significant minutes. He was 26 before he played for the Pistons. He was 31 when he signed his Bulls contract and even though that was clearly his tipping point he still got defensive second team on 10 rpg and 2 bpg. He's nearly 37 now and even though he's clearly showing his age, he's still been a starter for the last two years.
If you can get a DPOY in this draft especially, you have to do it. He'll be Joel Anthony at worst. Besides, IF he's Ben Wallace with 4-5 more years of that kind of productivity, you're looking at a first-ballot HOF-er.