Ya warlord level has nothing to do with anything, It's best to keep them low level so you can use the levels for free res during events. People pm me all the time 'how do you have such good fams at such a low level'
Portraits are determined by the best fam in your deployed brigade so when you are training fams it changes (to Meta2 in his case) but hes got a couple of L's in his PvP squad
The guy you're talking about made a fresh multi-account for this event (I forget the name of his main but If you spy on his board he says it somewhere). Its an exploit but its a good strategy
PvP matchmaking is still a bit of a mystery but you definitely get easier battles with new accounts / 3 and 4 man formations / and weaker fams. You will need either top tier fams or a tun of ammo to rank high regrdless