What is the height of the ceiling?

Then 3 pcs is sufficient (900-1200lm). Ensure you get quality downlights like Philips/Osram as their stated lumen output is true output.
Have seen Philips 1200lm beat those China branded so claimed 1440lm when we use a lux meter to measure. (122lx vs 100lx).
Also the Philips 1200lm only consume 12W whereas the China branded needs 18W.

Pila is a low cost solution from Philips. For own house use, I only go for Philips with at least 30KHrs (3-Year Warranty) for downlights. No point to skimp for a few pcs as the installation cost is way higher.
If you are concern with energy savings, look for downlights with efficacy of >95lm/W.

Same here which is the reason why I changed all my older downlights to LED downlights. Typical LED bulbs lasts 8-10KHrs offering 1-Year warranty. Better quality lasts 15KHrs and better efficacy.

Example as below:

PHILIPS E27 LED Bulbs:

10Khrs 1055lm 11W
15KHrs 1055lm 9.5W

To replace these E27 LED Bulbs downlight, we only need to replace it with 900lm LED downlight that is brighter and higher efficacy.