I want to buy a laptop for on the go and to play strategy games (anno, total wars, Europe universales, Planet Zoo). Which graphics card does the laptop need for this?
How much do you want to spend on the laptop?
Check out the system requirements for the games.
Then look at the values of the built-in graphics card.
Compare the values. The installation of a GrKa in a LAptop is quite special, so I guess because you ask the question that this is not for you, but rather for an experienced hobbyist.
The following applies to laptops: with the best graphics card that still fits into your budget. Because swapping later is not possible.
With Anno 1800 and 4K you also get a 1080 to the limit.
Around 1000 euro are okay.
Let's say love 1900x1080 with medium details.
980M, 1050ti, 1060, RX570
This will probably push the CPU to the limit rather than the GRAKA