I dunno. I'd think if it turns easily on the stands, then it should be okay. If the strut bearings were that bad, I'd think they'd show it there as well as driving.
When strut bearings are bad, they often squeak as you turn the wheel (a painful, nasty squeal...).
If there's too much positive caster, it makes the wheel hard to turn.
Wheel Alignment A Short Course
On another front, manual racks also have a tension adjustment set screw - red arrow, below.
It could be that it's just set too tight.
Here's a thread explaining how to make the adjustment:
Clark's Garage Message Board :: View topic - Adjusting steering tension on early, manual cars
It could also be that you have a fast-ratio manual rack. I recall seeing a thread recently that Porsche offered a manual rack with a quicker response (closer to what you have with power steering) - which would also make it harder to turn. I wish I'd written down the part number of that.
The alignment shop dude sounds like an idiot if he didn't know the caster is adjustable. I'd ask for my money back and find a new shop that actually knows 944's.