With Alakazam Stamina is as important if not more important than Attack.
A low Stamina IV can drop as much as 10% of Alakazams HP at lvl30 - and it has the greatest impact on his final CP of all the stats.
He has great attack...it is his survivability you need to ensure.
As said above...sometimes a high level evolve will do the job as well without the stardust investment.
While stamina IV is more useful in terms of both CP and effectiveness compared to an equal amount of attack IV, in this case it is only a difference of 2 stamina IV which is either going to be 1 or 2 HP less, while the difference in attack is 5 points.
Alakazam may benefit less than other Pokemon from attack IV but that doesn't mean it's worthless on him. Breakpoints still exist for Alakazam like any other Pokemon.
In this case I would go for the one with 15/13/13 over the one with 10/15/15 because there is no guarantee that the extra HP will make a difference, raid bosses hit much harder than regular Pokemon in gyms so they're much more likely to overkill you. 13 stamina is still great.
If you're sweeping gyms you can afford to dodge every attack and only take 1-2 damage per hit, that extra stamina can make a difference (though regular gyms are easy to beat so it's not a meaningful difference), but in raids where speed is also important you can't afford to dodge quick moves so when you're taking larger amounts of damage per attack there's fewer scenarios where that small bit of HP makes a difference, wheres attack always makes a difference even if only minor.