I feel so noobish for posting this. I've been unable to force getRange to work! It displays more posts than I want.
public function getCombinedNews($limit) {
$name = $this->Title;
$entries = DataObject::get("BlogEntry", "Tags LIKE '%{$name}%'");
$articles = $this->Articles();
$articles->merge($entries);
$articles->sort('Created', 'DESC');
if(isset($limit)) {
$articles->getRange(0,$limit);
}
return $articles;
}