SSL Cipher Order on LTM

I can't say the reason for the default order, though it has seemed in the past F5 has preferred speed over encryption strength. I have switched to using my own lists on sites that I need the highest security on.

Also, I would drop RC4 completely. See https://support.f5.com/kb/en-us/solutions/public/14000/600/sol14638.html Even if you upgrade to 11.6 to mitigate this attack, most people tend to consider it broken and not advisable to use.