As someone who was born in Coventry and lived in Leicester next door to one of your old Directors (his name escapes me now but was a twat) in Stoneygate, I can categorically state Leicester is not a bigger city than Coventry in terms of population or acreage. Leicester is a county town so has a good catchment, but so has Coventry with a north and south Warwickshire area that is massive. Both towns have identical A, B, C etc population profiles. Although I have not lived in Leicester since the late 90s, at that time, most of the asian and afro-carribean people I worked with supported Man U and Arsenal. Coventry has a lower population percentage from these groups. Leicester got lucky with the way they avoided points deductions and got a lot of money when it was most helpful.
You winning the Prem was awesome, but you are only bigger than Coventry at the moment in terms of football history and current performance. The world turns and these things change very quickly. Just look at Ipswich and Stoke.