Zogwort is awesome in a foot-slogging list. I don't think that a foot-slogging list should have nob bikers, let alone SIX of them....if you're taking a foot slogging list, take a foot slogging list.
As for Zogwort, you have a 50% chance of squigging an IC, not a 33% chance (you vs them, whoever rolls higher) every turn, which is a *lot* of fun. He works great in conjunction with a nob with a powerklaw against a unit. Here's the thing though:
Easy foot slogging army that will kick serious tail: squads of 30 boyz, nob+PK in each one, and the entire thing preceded by a 29 count gretchin unit with 2 runt herders. Those 31 models spread across your front lines give the rest of your army a 4+ cover save as you run across the field, and Zogwort really shines here with his potential to teleport, waaaugh!, or other crazy things until you get within 18" to do real damage.