Pavanne, is your property in the Landwirtschaftszone?

If so, you also need to check cantonal regulations. LWZ is generally regulated at the cantonal level, and regs often far exceed Gemeinde restrictions. Gardening in the LWZ can be tricky, as you have soil and drainage issues, certain types of plantings might not not allowed, certain species might be restricted, some might need the agreement of neighboring farmers, etc. Additional permits might be needed. Any garden design or work outside the scope of agricultural use (i.e., grazing) would need to keep LWZ rules as they apply to your property in mind.

So... if you are in the LWZ, then go with the firm that is on good terms with the cantonal office. As well as the Gemeinde. (If you are not in the LWZ, then ignore the above.)

But that aside - I'd go with the first firm.

I instinctively distrust any salesman in shiny shoes - let alone one selling gardening services. A true plantsman has dirt under his fingernails. Go with the guy in wellies.

That the guy from the second firm didn't really go into the garden would worry me - regardless of how good his ideas were, you need a garden plan that fits the property - ideas must be adapted to the lay of the land - which requires a fair bit of traipsing around.

Also - I like that the first guy came up with a decent quote without charging you for the Offerte. So in my book he wins on two points of principle.