Suedee,
I have to say I wouldn't get hung up on the flying qualifications or airbourne experience of ground instructors.
The fact that someone is an experienced ATPL does not mean that they can teach to ATPL standard. I would far rather have a good ground instructor who has never flown than an ATPL who is vastly experienced, but struggles to teach.
The majority of my groundschool in the forces was by engineers who got more pleasure out of pulling aircraft apart than flying in them. In fact most of them declared that pilots were mad for flying collections of nut and bolts in loose formation.
Getting back to the point, find out what the pedigree of the instructors is with regards to how well they teach and whether they meet your needs. This will be far more important than the flying qualifications they hold or otherwise.
Regards
Obs cop