You CAN use multiple drawing tablets at the same time with your computer.
However, you need to be know which specific scenarios work and some issues that might encounter. There are also issues that are specific operating systems that come into play.
"Using multiple tablets" can mean mean various things.
This scenario works:
2 or more drawing tablets attached to the same computer
where you are using then pen with only one of them at one time
This scenario does NOT work
2 or more drawing tablets attached to the same computer
With two people simultaneously using a pen on each tablet
Fundamentally a driver needs to talk to all the tablets
One driver and many tablets of same brand
If all the tablets are of the same brand - you can install a single driver and it will know how to deal with each tablet.
This works on both Windows and MacOS
Many drivers and many tablets of different brands
If you want to use brand X and brand Y tablets, you need brand X driver and brand Y driver installed.
On Windows, this usually leads to problems in my experience. The drivers interfere with each other. Some people seem to have no issues with this scenario. But I have experienced problems.
On MacOS, this works.
All modern drivers I've looked at let you configure each tablet individually. There's some way to "switch" which tablet the driver is configuring.
In the Wacom Tablet Properties app you will see the tablets shown at the top
In the Huion app, you can switch at the bottom
In the XP-Pen app, you can switch in the upper left
Each tablet can use a different pen. Of course, if you intend to switch between tablets it is convenient if you can use the same pen with each tablet.
You can use both pen tablets and pen displays together with the same computer.
Tablet drivers can occasionally get confused when you have multiple tablets. In my experience this has happened when I've been plugging them in and unplugging them back in very rapidly.
In those cases, I saw issues like it wouldn't let me use one of the tablets. The issues were was resolved by just restarting the tablet driver or restarting the computer.
In general I have not seen this kind of problem simply not rapidly attaching and detaching tablets to a computer.
Sometimes people want to use two tablets on a computer because they have two children and want each to be able to draw at the same time. This scenario does not work.
Let's suppose both children are drawing simultaneous on their individual tablet. The pens will "fight" and the pointer will bounce back and forth rapidly and it will be impossible to draw.
Wacom - YES
Huion - YES
XP-Pen - YES
Xencelabs - YES
Wacom Setup 1 (tested in September 2023)
Wacom Cintiq Pro 27 (DTH-271)
Wacom One 13 touch (DTH-134)
Wacom One 12 (DTC-121)
Wacom Intuos Pro Large (PTH-860)
Wacom Intuos M (CTC-6100WL)
Wacom Setup 2 (tested in September 2023)
Wacom Intuos Pro Large (PTH-860)
Wacom Intuos 4 XL (PTK-1240)
Huion Setup 1 (tested in September 2023)
Huion Kamvas 22 Plus (GS2202)
Huion Giano (G930L)
Huion Kamvas 13 (GS1331)
Huion Setup 2 (tested in September 2023)
Huion Kamvas 24 Pro 4K (GT2401)
Huion Kamvas 13 (GS1331)
XP-Pen Setup 1 (tested in September 2023)
XP-Pen Artist Pro 16 GEN2 (MD160QH)
XP-Pen Deco Pro XLW GEN2 (MT1592B)
Xencelabs Setup 1 (tested in September 2023)
THIS DOES NOT WORK - the driver explicitly says it doesn't support multiple tablets
Xencelabs Pen Tablet Medium
Xencelabs Pen Display 24