Against human players, I cannot imagine Swords to Plowshares ever being viable, as it is too easy for a single opponent to declare war on you to remove it. Of course, the incentive not to do that is that their cities might have the bonus too, but it is very easy for somebody else to declare war.
Perhaps +15% if smallest standing army, +10% for 2nd smallest, +5% for third smallest, would be better? It would be entertaining to see adjacent (and thus both have this religion) opponents reverse-arms race to get more bonuses.
As for the reloading thing, if that is fun go ahead and do it. ESPECIALLY because this is a single-player game, how you play does not effect anybody else's fun. And you can't reload in multiplayer anyway.
As for your attitude that randomness does not belong in strategy...what?! If there was no randomness whatsoever, then you could easily develop an algorithm to make the correct mathematical decision in all situations. This is why computers are so good at Chess, as there is 0 randomness. So at that point you are not using "strategy", you are memorizing the proper algorithm and using it.
Risk analysis is what allows for strategy. Possibilities that are so complex that you as a player can never memorize the algorithm, and thus no matter how good you get at the game you always have decisions to make, that is good strategy. Having to think and make decisions, not memorizing algorithms.