I am not sure the "spectrum" idea is as applicable in theology as in politics. Maybe on a very broad level, but there is a lot of nuance that gets lost looking at it that way. Then again, that is arguably true in politics, too. For all that people on both right and left try to make it a battle of opposites, there's a surprising amount of nuance if you actually look into people's views.
For instance, process theology and Vosper's spiritual atheism (or whatever you want to call it) both fall at the progressive end of any attempt to put theology on a line, but they are distinctly different from one another in many ways. Similarly, Pentecostals and conservative Baptists fall at the "conservative evangelical" end but are, again, distinctly different from one another, no matter how much progressives might try to tar them with the same brush. And there are conservatives (people who want to maintain traditional theology and morality) who are not evangelicals. And, arguably, there are evangelicals who fall on the liberal to progressive end of the spectrum.
And "centrist"? Dear Lord, that is so broad as to be meaningless, isn't it? At least on the political spectrum, you can have someone who has conservative fiscal policies (e.g. maintain free enterprise, minimize government debt) but liberal social policies (e.g. supports social programs to some degree, supports the rights of women, LGBTQ, etc., and so on) that can then be defined as "center" since they clearly fall in between the left and right.
But in theology, where you're already probably dealing with more of a "cloud" or at least two-dimensional graph than a line, centrist is going to be harder to define.