I have flown many times to Schiphol and using a Dutch passport I get out of the place in 30 to 45 minutes. The time you spend extra waiting at passport control is time you wait less for your luggage.
Most of the time the line for 'all passports' is rather short but slow going.
From the exit of the secure area (the green channel) to the train should not be more than 5 minutes, follow the signs.
If possible, look up the platform before you even arrive in the Netherlands. Most trains always leave from the same platform and if you are in a rush, it helps if you know which one you should have.
But I think you are leaving yourself enough time if your plane is not delayed.
I missed that you want to catch a train within the Netherlands. Those are without reservations, so you can catch any on the day, even when you buy a ticket online. Those trains run very often, you might even catch an earlier train rather than a later one. Most of those trains leave from the same platform every train that leaves on a given day or even all the time. But do read the sign on the platform because there are several trains in turn leaving from that one platform.
I have been stuck in passport control quite a bit longer recently, 1 hour for one, more than 30 minutes at an other time. And that was using the 'fast' EU passports only options. It may have been the time of day, but do leave enough time for getting out of the airport when you book a seat reservation on a train.