1) httrack wasn't able to crawl anything for some reasons. wget only with special flags available in the latest version.
2) All the links are broken. Wiki have their own linking system between pages that are processed on the fly. The archive with all links hardcoded to wikidump.example.com/wikidump/page really doesn't work in place.
3) More challenges with saving pictures and attachments.
4) Unicode characters in some pages, that broke the page and/or the crawler.
5) Infinite crawling and a ton of useless pages. Consider that every URL with a query string is a separate page. /page?version=50&comparewith=49
6) Crawling large amount of documents takes forever. Could be an hour wasted on each try. Consider tens or hundreds of thousands of unique URLs to save, see point five. Really wish the crawler could parallelize and run on the same host as the wiki.
You'd need to process each page then data mine it.