It's 100% down to the number of turnstiles... 4 entrances in the NS for 2500 people, predominantly turning up within 45 mins of KO.
The ES has just 1 turnstile for home fans (I think)... For me I don't think it is a problem if the club just recognise that if the queues are still large 5/10 mins before KO, then get the mobile scanners out and open the exit doors to allow fans through quicker... Yes this might mean more fans turn up later for knowledge of getting in this way, but at the end of the day, fans get in...