Yes, the 6 kg is the total payload for both monitors together, not per screen. So for 2 x 27" monitors you have to choose two very light models; many normal 27" monitors are already around 4 to 6 kg each with a stand and therefore do not fit.

Important here:
- The stand is designed for 2 monitors with a maximum of 27".
- The total load capacity is 6 kg.
- If a single 27" monitor already weighs close to 6 kg, it is not suitable for this stand.

To your example:
- A Dell P2422H is actually much lighter than 5 kg in practice if you only consider the device with stand; this explains why it is mentioned as a reference.
- With 27" monitors, you therefore need to look at the weight with the stand, not just the screen size.

I can't tell you for sure from the information available which 2 27" monitors will fit because I don't have a complete list of weights for specific models. It makes most sense to choose according to this criterion:
- Weight per monitor together with the stand used as low as possible
- VESA 100 x 100 mm
- together a maximum of 6 kg for both monitors

I'm not quite sure about the exact model recommendation. The available information does not fully answer this specific selection. It's best to ask the Community if you want to check specific 27" models against each other.