Lateral stretching is fine Eastpoint. Taking 2 early from 10 still leaves your 8 and relieves some revision stress. It does no harm at all.
But where did you get the notion that now it is "8 at the same time" from anyway? Which universities state this? I just looked the four unis where I have worked, and been involved at various times in admissions:
Cambridge: GCSE requirements. Apart from Med and Vet there are none, though they say that 4/5 As or A*s is the norm. No restrictions on early entry.
Oxford: "We do not have any specific requirements for GCSE grades, though higher grades can help to make your application more competitive. Successful applicants typically have a high proportion of A and A* grades."
UCL: No comments on early entry.
King's London: Does comment, but only to the effect that a grade from a year early is treated in the same way as one take normally.
For A levels if you take one a year early then I know some Departments may ask for grades on 3 more to ensure workload management OK, e.g Imperial Physics, but at GCSE there's no evidence among the top group that they care much about GCSE timings. It's also of note that they are more interested in a good handful of top grades at GCSE than doing 12 or 14.
The prejudice against early entry I think comes from schools' obsession with performance tables, where only the first entry counts. Schools who have kids who are judged to be capable of achieving A* a year or more early should allow them to do it if they want to and get it out of the way.