Attrition (loss of troops) should be a factor in the tie breaking process. Not as a step by itself but maybe it could be combined with time remaining as a "penalty" and reduce the time by 1 second for every "troop unit size unit lost" (a lost tank would be an 8 second penalty while a lost rifleman would only be 1 second). The way Warships are now, all too often the fastest player wins even when both players completely clear the deck of the opposing ship. At this rate, Warriors win because they move the fastest as long as you can keep them alive and tanks/scorchers rarely win (not to mention the wildly inaccurate Grenadiers). Having time as tie breaker is certainly a worthwhile tie breaker but to not consider the casualties at all in the evaluation of a battle, any battle, is a bit of a oversight.
I like the idea. However, it would be unfair because some strategies, such as all-rifleman attacks, warrior rushes, and zooka rushes tend to have higher casualties than a tank-medic strategy. Also, it would encourage players to not deploy all of their troops, since there would be less potential casualties.
That is exactly the point. All riflemen or all warriors move faster but sustain higher casualties and thus the point of using casualties to balance that out by using casualties as a factor. 8 riflemen lost would be the same as a single tank loss. If your warriors finish 45s faster but you lose 15 warriors then it would be a tie with a T-Med that had no losses. If you lose 65 riflemen but finish 60s sooner then you'd lose against an opponent that had no losses at all.