I like to think of it more as best seam bowling allrounder as opposed to second best allrounder overall. I realise this isn't actually the thread you started and you're within your rights to set your own rules to your thread, but debating the second best of something always seems a bit ekh to me, like I could probably do something more interesting with my time. So that'd rule out Nabi and Shadab.
Colin's the one who could probably change my mind the quickest. You probably couldn't ask for more with the ball as a batting allrounder -- awesome when conditions suit, tight when they don't -- and he's done well the bat so far. He has a really good (albeit basic) batting technique too -- he's very aggressive with the bat but tends to play classical cricket shots, especially to the quicks. I think I'd rather have him as a bowling option in my side than Stokes (unless I'd been given forewarning of the conditions and they were going to be dry, of course), which means if he equals him with the bat too then he's there in my mind. It's easier said than done but it's very possible.
The CW opinion of Holder kind of confuses me a bit. When people said his batting was already very good and that he needed to work on his bowling, they meant in the context of him being a bowling allrounder, right? Because at no stage have I ever thought his batting was better than his bowling. That seems like an opinion from Mars to me.
Overall I agree with your sentiment, but I don't want to trump spin with seam for the sake of being best or second best. We all know Shakib is well respected (he was beating Botham in a CW poll on here for months).
There is no shame at all to second best, someone has to bowl up hill and into the wind, someone has to bat 3 or 4.
So whether it is spin or seam, makes little difference to me. People can debate Roston Charles and I'd be happy.
I do come from a country where the spin bowlers have been Howarth, Boock, Bracewell, Patel (Dipak, I am not crediting Jeetan here), Hart, Vettori, Craig and Santner, but that doesn't mean I haven't seen Kumble, Murali, Warne or Ajmal (and Ashwin and Jadeja in Asia) do their thing neither.
Spin is relevant. So is seam.
I think Shakib is very good. Asian batsmen in tests in Asia may find him easy scoring, but he has stood up to bad and good NZ teams with both bat and ball. He beat Aus at home in a test singlehandedly. The guy can play. We all know this.
Colin was Hesson's biggest right call and he made many. He got some wrong, no doubt. But no cricket pundit, not even NZ ones's expected CdG's test success to this degree. Hesson can go to his grave knowing he got that one right against the wind of popular opinion. Well done Hesson. Some sections of the media still doubted it
AFTER Pak And SA. When he was pretty much already proven as a success.