Topic: Churchill Design
I like Robert's answer and the commentary around it stand as a great answer. The question that keeps getting asked is 'why doesn't the guy with the most points win, like all the other games. I just did a rudimentary search on BGG and there are 50 electronic pages of games (5000 titles) that play this way, so if folks want their regular experience, lots of choices and I did not want to add one more to the list.
First and foremost I am an historical boardgame designer. Not a historical themed boardgame designer. If you are in a military alliance and all you do is run over your Allies the historical precedent is your former partners will ally against you. Review Napoleon's modis operandi to see what I am talking about.
The victory conditions are designed to reflect this historical alliance attitude and structure. You are not held to it as you can just go for the get the most VPs, and extend the WWII struggle for national gain that would create the narrative for WWIII. So, its included as it was a serious possibility if some of the Big Three fell off of unconditional surrender which is an American not a European concept.
Last night I played in a really interesting Churchill game where I was the US and won by 2 VP in a condition 1 victory. My goal when I play is to have a good time, so at the beginning of Potsdam the Germans had surrendered where the Western Allies won the race for Berlin with the Soviets in East Germany, so Roosevelt and Churchill had gained a net four VPs over the Soviets who had been in first place the entire game by less than 15 VPs. Churchill was now in first by 10 points over my last place US with the Soviets sandwiched in between. So, the war would likely be a VC1 or VC3 (conditional axis surrender) outcome.
The discussion was around how the USSR conditional issue should be resolved from the perspective of each side. It was our view that the UK wanted the war to end to win a VC1 as being in first in a close VC3 game is usually a defeat, which on my part is intentional as you avoid chaos when you are in a close game. As the US I had my late game Pacific VP opportunities as a way to climb back into first, so I wanted the war to end.
The Soviets had no opportunities for any additional military VPs and calculated that he would be in last place, but close enough that the chaos favored him, so he did NOT want to declare war on the Japanese. The USSR needed to win the agenda segment to make that happen. As it turned out it almost happened as the British had no 5 or 4 cards on their last draw and played a 3 card for the Agenda segment. Since both the USSR and the US anticipated a 5 play we both played our Chief of Staff cards hoping for a 6. We were stunned by the UK three play and as it turned out Zhukov tied with a 3, but the Imperial staff plus 1 carried the day and the UK won the agenda segment.
We then discussed that the Soviets needed to win the Global issue (the UK had two in their corner for +10), but the campaign card was 10C and the British had the global issue on their 6 space. I wanted to divert my two Allies, so I helped the USSR get the Global issue onto their track and I quietly won three issues and the conference for 3 VPs that ultimately gave me a 2 VP win once you calculated in my successful advance into Iwo Jima.
The point of all of this detail is the victory conditions are a major strategy point in Churchill beyond having more. It is not only how many points but the character of the post war world that determines the winner. So, when the OP (what does that stand for?) asks, "So my real question is why was the normal "trailers cooperate against the leader" mechanism not sufficient for this game?" That is why...