I have been absolutely loving Knight Commander Pask. The boosts he gives to his squad and the tank he's in are just spectacular. You are very correct about the Ordnance weapons though, sponsons and them just don't get along due to Snap Shots (though Pask giving the unit Preferred Enemy will see at least a few re-rolls).
I have been playing Pask with two LRBTs just lobbing BC shots out. Almost impossible not to wound with Preferred Enemy, Pask's tank's re-rolls, and S8/AP3. Plus, Split Fire-ish order if you're feeling confident.
Also, Pask in an Executioner (pie plate plasma) with two LRBT's.
Also, Pask in a Punisher (20 rending shots
) with an Executioner.
Eventually I would like to try Pask in a Vanquisher with two LRBTs, but I will need to get a couple more tanks that I can magnetize properly. Just bought a pretty serious (around 3-4k) Guard army off a buddy, still getting used to the models I have and the new 'dex before I get spend happy. Not to mention my other four armies...
Sorry for my poor english, it is not my first language...
Don't suppose your first language is French with the Canadian flag flying, eh?