I would beat a team of Bautistas with a team of Heywards, and it really wouldn't be that close. I expect the Heywards would win the division by double digits. It is dishonest argument to focus only on offense and hand wave away the defense and baserunning as it is EQUALLY as likely that WAR UNDERRATES defense as it could overvalue it.
This is a goofy argument but I'll play:
I will assume that you aren't saying literally a Bautista at every base versus a Heyward at every base since that makes no sense - who knows if Heyward can catch (and produce the same WAR) or that Bautista can play 2B? So, I will assume what you mean is that you will take position players with Heyward's WAR earned at the same ratio as Heyward but adjusted for his position and the same for Bautista. So, if Heyward hit 13 HR last year then all positions do that and if Heyward developed a significant portion of his WAR from baserunning and defense, then each position does so at a similar rate, and the same for Bautista.
So, you have a team of lighter hitting, good base running excellent defenders against a team of power hitting, ok base running average defenders (or at least passable).
Heyward hit .293 last year with 13 HR, 56 BB and stole 23 bases getting caught 3 times combined with his base running and defensive value for a WAR of 6.5. His career 162 game average is .265, 18 HR, 73 BB, 17 steals and caught 5 times.
Bautista last year hit .256, hit 40HR, BB 110 and stole 8 bases while being caught 2 times for a WAR of 5.1. His career 162 game average is .250, 33HR, BB 93, 7SB with 3CS.
So, using their 162 game average in HR (HR cannot be defensed) Heyward totals 18x14=252 runs, assuming a team of 14 position players, (if you want to limit to the 8 on field guys then 18x8=144 runs). Bautista totals 33X14=462 runs or (33x8=264). The run total assumes ALL solo HR.
But, but wait! what about if they aren't solo HR, you ask? Well, Bautista's career OBP is .368 and Heyward's is .351, so Bautista theoretically has more guys on base when the HR is hit making the run difference even more pronounced. But, you say the Heyward team has superior defense and would allow less OBP that the Bautista team would allow? Fair enough. But, remember that Bautista draws walks at a significantly higher rate than the Heyward team and you can't defense walks. And the Heyward team is hitting against a team full of adequate defenders which probably balances any gains the Heyward team might get from the +/- effect of having a balanced defense to face instead of the ups and downs faced nightly in real ML play. And remember that Bautista by definition hits the ball harder and has more fly balls which has an effect on the fielders.
I think it's pretty easy to see that given identical pitching staffs, the Bautista's easily win because of the indefensible nature of HR and BB and the significant difference in OBP. Heyward probably closes the gap a little by taking the extra base and stealing at a little better rate. But those actions don't necessarily guarantee a run.
For instance: Heyward 1 hits a single. Heyward two strikes out. Heyward 3 BB. Heyward 1 and 3 double steal. Heyward four grounds out to short. Heyward 5 grounds out to short. Heywards: 0 runs
Bautista 1 K's. Bautista 2 K's. Bautista 3 hits a HR. Bautista's: 1 run
But what if Heyward 4 grounds out and Heyward 1 takes home with Heyward 3 staying at 2B? OK, what if Bautista 2 walks instead of K's?
HR Power is guaranteed production. The batter drives himself (at least) home.
The only way the argument works that Heyward is more valuable than Bautista is if you are banking on age and potential.