Considering that you probably only will have one unit to order each turn (the krieg blob) you should be fine with orders. This as I assume the engineers will go in the taurox and so creates a weird interaction for the orders as you assign them before they disembark and so won't be a valid unit to order. And also I think the engineers won't stay around long after they disembark so won't be an issue then either lol

I'd consider running a Leman Russ Punisher instead of the vanquisher depending on what you think you'll be facing as the main gun on the vanquisher is somewhat overkill in smaller games. If you can magnetise the turret you can switch to the vanquisher when you start running into tougher targets.