The Go Ahead website states they run "7000 buses"
Stagecoach say they have "8400 buses"
We are a leading quality public transport provider in the UK. More than 3 million customers a day trust our greener, smarter and better value bus and rail services - and we are continuing to grow.
www.stagecoachbus.com
So they are already way ahead of First who run, by my counts, 6000 buses
By my calculations its around 4000 buses outside London, 1000 in London and around 1000 in SPS/Aircoach/Ensign/Coach companies
Considering they've only fairly recently bought RATP Dev Transit London, First must have been the third biggest for many years, this time last year they perhaps had less than 5000 buses
Therefore the closure of Kernow with 93 buses is trivial in the grand scheme of things