Hello,
When you turn on, "Sitemap" in Sef Translate for your site, Sitemap will translated to all languages which you set for translation. You will take many sitemap on every your language. But for that you need select option "Site Map Component" - we support only these components "XMAP", "JooMap", "JM Sitemap" - you not selected that option. And again please limit languages number for translate.
Translate algorithm, That methods as we do page parsing and move for translate to Google or BING Translate API.
We do that with break web page to small peaces and next translate these small pieces.
Thanks,
OrdaSoft team