If you use the oneconnect every req from the loadbalancer will take an new loadbalancing decision for each tcp req towards you servers behind the ltm. If you don't use the oneconnect in the way you plan, or the "lb detach" in an irule the loadbalancing decision will take place in the first tcp req in the session and all other req will use the same server.
If you use Akamai for example who use some varios type of pipelineing and tcp optimization you must use either oneconnect or lb detach. Or you loadbalancing will be very wrong.
BR Maddox