The curious case of the back-up spinner

Consider the bowling figures of these 4 spinners in IPL:
                     Matches    Overs      Runs     Wickets    Avg         Eco. Rate
Exhibit-1        6              22           161         7             23.00           7.31
Exhibit-2        4              16           114         4             28.50           7.12
Exhibit-3        5              19           106         4             26.50           5.57
Exhibit-4        5              18           133         3             44.33           7.38

If you are in charge of selecting the national squad and have been asked to pick one out of these four bowlers, who would you pick? Exhibit-3 has an exceptional economy rate for a spinner in T20 cricket, he is the most experienced of the lot, but hasn't represented his national team for a while now. Exhibit-1, on the other hand, clearly leads the way with wickets and average, has been playing in the national team and has also dismissed the leading run scorers of IPL by some wonderful traditional spin bowling. Exhibit-2 has been steady and has recently played for the national team. The one who is not doing so well, in the above figures, is Exhibit-4 and he also hasn't played for the national team for a while. Now, let's also clarify that there is nothing much to choose between these four when it comes to batting.

So, who would you pick now? The best bet looks Exhibit-1. If you want to take a bit of risk and purely go by form, then you might go for Exhibit-3. Or if you want to play a bit safe and go for the steadier option, then pick Exhibit 2. Can you think of any logic based on which anyone would pick Exhibit-4 above other three?
Well, unfortunately, our selectors don't seem to base their judgment on any sort of logic that a rational human being would apply (which probably shouldn't come as a big surprise, given that the chairman of selectors is K. Srikanth).

If you haven't guessed already, here are the four players in question.
Exhibit-1: Amit Mishra
Exhibit-2: P. Ojha
Exhibit-3: M. Kartik
Exhibit-4: Piyush Chawla

Why Chawla was selected in the T20 world cup squad will remain a mystery to me. Given that India hasn't played a lot of T20 internationals off late, it was probably a good idea to base the selection mostly on the IPL performances. Or the selectors could have looked at the performance in ODIs. But none of this explain why Chawla was picked. The selectors probably know something that rest of us don't. Chawla must have some hidden talent (which, one must say, he has done well to hide so far from the world).
The best part of this entire issue is that we'll never know whether the selectors are right about Chawla. Given that Jadeja would be picked in the team as the back-up spinner and we have Pathan/ Yuvraj to roll their arms overs, Chawla may never get a game.