Are you worried about difference in readings? Or oil consumption?
If readings, do not worry, as I believe, first and original readings matter more. You went to the garage on the recommendations of one of the senior members here, so readings and garage, dono ki guarantee hai k wo theek hain!
Don't worry.
Regarding oil consumption, I believe it to be normal.
And if engine is weak, then there are many other symptoms for a weak engine, like high fuel consumption, smoke from the exhaust, massive drop in engine oil level and engine pick, power and performance.
If you are not experiencing any such things, then engine health is fine IMO.