automatic draw

In games with ascending cards, in situations where trades are worth much less than total army strength, and total army strength is over 500
or so, the game typically ends in a draw, and certainly would if all players played rationally (i.e. played to win).
So for example, when trades are over 100, and total army strength (of the weakest player) is around 500 or more, there is no incentive to kill anyone.
Continents are worthless at that point. I see two solutions a) Game could automatically end in a draw when such conditions are met, or
 b) change the ascending card trade values for high trades, so for example, when card trades are over 100, perhaps instead of going up by
5 armies each trade, they go up at a faster rate. I'm not sure what is best, but maybe increasing say at 20 or 30% each trade. A 20% increase
would be, trade 100,next trade 120, next trade 144 etc. My guess would be that this might fix the issue, but obviously some trials could
determine that. Any thoughts?

The automatic draw idea is not a good option. But the getting bigger troop bonuses for card trades may be viable!
Get the mathematicians on it, there is a real possibility this could work.

yes...option (b) would be my preferred option. It would be nice to see more games ending without being stuck in a draw.