From what I read, they have an hard limit on the € they can move with SEPA using their polish bank.
It is not improbable they follow a queue, but, when the next order is too large, they fit all following smaller orders they can.
For example: if they have 999€ they can move but the next order is 1000€, they look at the following orders to fit together as much orders as they can (300+500+100+50+49=999).
I would do so