Complex sentence: Hosts Canada celebrated its medal hall, which was the second best after the United States; however even some considered it a disappointment, since the US amassed the most medals with a mostly second-string team while Cuba managed more golds than Canada.
Split into simpler sentences: Hosts Canada celebrated its medal haul, which was the second best after the United States. However, some considered Canada's results overrated, since the US amassed the most medals with a mostly second-string team while Cuba managed more golds than Canada.