Do you agree with historians who have argued that Sparta was a forerunner of contemporary government system or would this be a misleading assessments?

One can't agree with those opinions. They can be misleading.

Sparta was a militaristic state was ruled by two kings and a council of elders, and whose focus was to prepare its citizens for war. It was not a democracy. The Greek city-state that is usually referred to as the first democracy of history was Athens. During its times of splendor, a city council openly debated issues in Athens. Though only free citizens - slaves were excluded - could take part, it was a unique case of an open political system, because tyrannical rule by emperors or kings was the norm on those days.