I hope Oda doesn't make Momo strong just by turning him into an adult. That would be Force Awakens terrible writing and insulting to Luffy and Zoro who spent their childhood training like crazy in the harshest of environments for our MC.
Its like expecting an 8 year Kyrie Irving, Kobe, Lebron being as good as their 28 year old incarnations by magic. The countless hours of training to master every facets of the game. The practice games and 1 vs 1 to gain the experience and muscle memories in every situations. The countless victories and losses you endure growing up to become better. The grinding, hardship, and discipline are what make them elite athletes.
"I thank my father," Irving said. "He did things the old-school way. No shortcuts. Nothing guaranteed."