Pro-Rata Order Matching on Eurodollars

I have been doing a lot of simulated trading on Eurodollars.

The simulator used FIFO matching and Eurodollars uses Pro-Rata - not ideal.

I was wondering if anyone with experience could let me know the average number of contracts that are typically required at the bid or ask to be filled relatively quickly.

Would 10 contracts be viable in the Eurodollar market for fills under Pro-Rata, or would I be waiting until price clears through the price level to be filled.

Thanks!