As Paul Perrin says - Point of fact - Tommy Robinson is not a member of UKIP - he cannot join because UKIP (unlike any other party) have a blanket ban on former members of EDL, Britain First, NF and some other similar organisations. He is however an advisor to Gerard Batten (no idea if this is a UKIP financed role or not though). The Brexit Party is primarily setup for disaffected Conservatives so they can make a little rebellion then return to the Conservative Party - it is the 'Tory pressure group' that UKIP was always accused of being. But UKIP's objectives are to be a 'real' party.
Other than that, these two are spot on.