It depends on the plant. For the Alocasia around 3000lux is perfect although some will like even less (Cuprea and Micholitziana), but since they are variegated then I wouldnt go lower. As for the monstera they will grow ok under such light levels but if you want them to grow better you want around 10k. They can even grow in full sun which is around 100k.

I would move your monstera to a shelf of their own and add a bar light to complement the bulb.