According to Priesdorff, Soldatisches Führertum (Nos. 1182, 1318), the correct names are
Karl Leopold Heinrich Ludwig von Borstell (30.12.1773 - 2.9.1842)
Prussian Generalmajor on 9. May 1812.
Karl Heinrich Emil Alexander von Borstell (2.2.1778 - 11.7.1856)
Prussian officer until 1807, 12 January 1808 permission to enter foreign services, in 1812 Westphalian Major. 7 December 1813 re-entered Prussian service as Oberst (colonel, his patent being postdated to 7 February 1814), Generalmajor in 1818.
Both were sons of the Prussian general Hans Friedrich Heinrich von Borstell (28.2.1730 - 26.11.1804, Priesdorff No. 787).
Two other brothers died in combat:
Hans Friedrich Georg Ludwig Wilhelm (1770 - 14.9.1793 at Pirmasens)
Ludwig (1771 - 11.4.1793 at Kostheim)
In the entry on their father, the names of the surviving brothers are given as
Ludwig Karl Georg Leopold
Karl Alexander Emilius Heinrich
which, confronted with the later entries on the two younger generals themselves, might be an outdated info.