As someone growing up in the US where we think along the lines of the American Revolution, Cromwell Co. come across as very confusing.

They go so far as to execute the king (that isn't something that seemed likely had by some strange reason the American's captured the king (some good fan fiction there)) and yet as far as I can tell really don't seem to have much of a plan / do much to establish much at all after that, and sort of roll over at the end.

It always seems very muddy with all sorts of religious motivations (that admittedly I find hard to understand) from the outside.

Then again the tradition of 'Parliament' (speaking in a larger historical sense) seems to swing wildly as far as its loyalty to the king, or lack of it, power, or lack of power, and so forth.