For example, here's the disunity within Presbyterianism:
35,000, huh?
Let's grant that Catholic apologist-types beat the 33,000 denominations drum too much and don't really pay attention to the commonalities that exist in much of Protestant theology. Let us also grant that Catholic apologist types often don't pay attention, in such polemics, to the divisions in our own house.
-- from the thread The Perspicuity of Scripture and Other Creation Myths
1. Do not allege that there are 33,000 Protestant denominations. This tally comes from the 2001 World Christian Encyclopedia, and it includes all denominations and paradenominations which self-identify as Christian, including Catholics, Orthodox, Protestants, Old Catholics, Mormons, Jehovah's Witnesses, Seventh Day Adventists, Gnostics, Bogomils, etc. And even so, the number is too high. The World Christian Encyclopedia artificially inflates the number of Catholic "denominations" by counting Eastern Churches in communion with Rome as separate denominations. It likewise inflates the number of Eastern Orthodox "denominations" by counting Churches in communion with each other as distinct........even if we could arrive at an accurate tally for Protestant denominations (20,000?), we still could not blame the whole of that number on Sola Scriptura. Some of these churches share substantial unity in faith, even if they are juridically independent (perhaps due to geography). And much of the disunity of faith within Protestantism, at least in the developed world, stems from efforts to subordinate the authority of Scripture (e.g., to various sexual perversions). In reality, if every Protestant denomination were serious and consistent in affirming and applying the rule of Sola Scriptura, the spectrum of Protestant belief would be significantly narrower. It bears emphasizing: the only thing for which we can directly blame Sola Scriptura is the extent to which it fails to provide unity in true faith and morals to those who sincerely adhere to it, e.g., "orthodox" Lutherans, Presbyterians, Baptists, Anglicans, Methodists, Pentecostals, Campbellites, etc.
-- from the thread Unsound Sticks, or, Arguments Catholics Shouldn't Use
When this figure first surfaced among Roman Catholic apologists, it started at 20,000 Protestant denominations, grew to 23,000 Protestant denominations, then to 25,000 Protestant denominations. More recently, that figure has been inflated to 28,000, to over 32,000. These days, many Roman Catholic apologists feel content simply to calculate a daily rate of growth (based on their previous adherence to the original benchmark figure of 20,000) that they can then use as a basis for projecting just how many Protestant denominations there were, or will be, in any given year........If the Roman Catholic apologist wants instead to cite 8,196 idiosyncrasies within Protestantism, then he must be willing to compare that figure to at least 2,942 (perhaps upwards of 8,000 these days) idiosyncrasies within Roman Catholicism. In any case, he cannot compare the one ecclesial tradition of Roman Catholicism to 25,000, 8,196, or even twenty-one Protestant denominations; for Barrett places Roman Catholicism (as a single ecclesial tradition) on the same level as Protestantism (as a single ecclesial tradition)....
....In short, Roman Catholic apologists have hurriedly, carelessly—and, as a result, irresponsibly—glanced at Barrett’s work, found a large number (22,189), and arrived at all sorts of absurdities that Barrett never concluded. One can only hope that, upon reading this critique, Roman Catholic apologists will finally put this argument to bed. The more likely scenario, however, is that the death of this argument will come about only when Evangelicals consistently point out this error—and correct it—each time it is raised by a Roman Catholic apologist. Sooner or later they will grow weary of the embarrassment that accompanies citing erroneous figures in a public forum.
-- from the thread 30,000 Protestant Denominations?
For example, here's the disunity within Presbyterianism: