Well they'd certainly built up their tail to compensate for their top order. I'm not sure either Starc or Agar would've got the nod otherwise, purely on bowling ability.
I'd actually forgotten how little Broad bowled in the 1st innings. His being fit and able this time round will take some of the pressure off Anderson, but I'd prefer to see Bresnan picked over Finn. If England score as poorly in this test then we simply haven't got the runs to play with to allow for Finn's average. With Bresnan you can be fairly certain he'll hold an end, whilst also hoping he'll contribute a few with the bat.
I'm not sure Finn's form is actually all that bad though. He had a terrible session on day 5, but had looked OK before that. He's a bowler who can make unusual things happen, but he's always expensive. For me I'd always take Bresnan or Onions as 3rd quick as you've already got a player who's prone to inconsistency in Stuart Broad - a fine wicket taker on his day, but off it he keeps bowling all that short stuff that costs us. You can't carry two players like that in a 4-man attack. For me the line-up needs someone you can turn to for reliability.