Here in verse 19, the 1830 compositor misread shiblons and set it incorrectly as shublons. Earlier in Alma 11, he set the word correctly as shiblon (twice in verse 15 and once in verse 16):
The 1840 edition restored the original shiblons here in verse 19, a correction that the RLDS textual tradition has consistently followed. The LDS textual tradition maintained the incorrect shublons until the 1920 edition.
Summary: Maintain the spelling shiblon throughout Alma 11, including verse 19.