HM-11 Max Data Rate for in order receive between modules.

Hello,

I'm currently trying to run data through the HM-11 and receive it on another module. My main question is.

What is the fastest send and receive rate possible to send and receive the packets in order?

I currently have the baud rate set to its highest value which is 115200, however I'm still often receiving packets out of order on my Arduino when I don't place a delay in the send. If I delay(100) then the packets come out in order however, I would like to have a delay of 0. Is there any way to guarantee that the bytes are sent in order. I'm only sending four bytes between the modules which is much lower than the 20 byte limit. I'm reading the packets between the devices with Serial2.readBytes(input, 4).