So after working with a different TSE and doing some digging we found 3 things causing this huge growth.
1) Hp Proliant AMS issue - fix is to downgrade ams or turn it off (known issue in various communities and above poster, that I just saw)
2) bad nic on 1 host (of 250), was creating 5 event every 3 seconds - fix disabled nic
3) local datastore on a single host had a RAID problem - was giving a vmfs datastore error, this created 900K event in 22hrs
The hardest part was finding these. The first 2 showed when you exported the events list from vcenter, but did not show which host was creating the errors, so that was clicking through 250 hosts to find it; The third could not be seen through vcenter and I pulled the vpx_events_arg table from sql into excel to get that one. Hope this helps other and need to put in a feature request about exporting more info.