If Smash is 10k lower than Brawl's UK debut, I wouldn't call that a flop. Black Friday week is hardly a typical week at UK retail. It's obvious titles that would otherwise chart fairly highly (OR/AS charting 3 or 4 places lower than X/Y's debut despite 15-20% higher unit sales) have been impacted by Black Friday. I think Black Friday is a far bigger reason behind Smash being 13th than stock shortages, the solus edition of Smash is readily available.
More concerning about Nintendo's strategy in the UK/Europe was the complete absence of bundling or discounting this week. There were some great Wii U basic bundles recently and coming in the near future (Basic plus Captain Toad plus 4 games for £220ish on Zavvi in January), surely a Wii U basic/Smash day one bundle at an aggressive Black Friday price couldn't have gone amiss? Sure, I get they need profit, hence no price cut, but temporary, one day discounts could have shifted quite a few units, got Smash into more homes and got more people buying amiibos and Wii U software in the next few weeks.