Since you're dealing with a real locksmith, it's a simple matter to have 2 tiers of key.
You have the "master key" which works every lock in the house.
Then you have the "contractor key" which only works certain doorknobs (but not the deadbolt there).
The special-pin method (sacrifices 1-3 bits of entropy)
Mechanically, this is done one of two ways: ...
How handy are you? On this forum, I assume that you know which end of the screw driver to grab.
The big difference is the hassle of re-keying multiple locks if you want to deny a keyholder access.
Getting a lock rekeyed is straight forward. You don't even have to have the lock smith come to your house. Remove the locks, take them in, and a decent smith ...
If you lose the keys, or need to give them to someone who you later come to distrust, or post a picture of them on the internet then you'll need to change both locks instead of just one.
If this is just two doors, then it's not really a big deal - slightly more inconvenient if things go wrong weighed against slightly more convenience in everyday life.
If they are just standard doorknob entry sets, I see no reason to key them differently. If you add deadbolts, then those should have different keys. I have often encouraged people to install a deadbolt without a key for additional inside protection but maybe not a good idea if you have small children or a spouse/partner who gets mad easily.