We have never had a problem, gone thru many times with both Mum and Mum in Law, all living diferent addresses, own forms then this Easter took a friend, no relation different address, own form, again went thru all together. I think you have to be unlucky to have them seperate you.
Immigration officers might look scarey but talk to them and they are usually friendly people. Just put yourself in their shoes sat there with foriegners throwing passports at them and grunting. Make conversation and 9/10 are very friendly just doing a very repetative job.