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I think it's more a personality type.
This is very much anecdotal, but overwhelmingly the tories I know are crack-on, don't get bogged down in details, it'll be fine if you believe hard enough types. Conversely thise on the left are more critical. Doers vs Thinkers, I guess. I think it's much easier to work together if you're the former personality type - see how Pro-immigration Singapore-on-Thames Tories can sit in the same party as protectionist racists.
In any event you've got to a bit careful about how you draw your conclusions. I know someone who wrote their masters dissertation on Party cabinet styles from WW2 to Brown and their conclusion was that Labour were more dictatorial and less collaborative.
Kinda makes sense if you say the first lot are people who think about others and the second are only out for themselves, so it's easy to ignore the bad bits about the cunts you're in league with. But there definitely needs to be some nose holding from the left over smaller differences to make the big difference of winning happen.