I mean, Luffy's had plenty of smart moments, especially during fights when he figures out his enemies' weaknesses (figuring out Crocodile's weakness to water, how to get past Katakuri's future-seeing Haki, using his past experience with Magellan's poison to defeat Caesar's toxic gas, etc).
18:50 Sam's footprints weren't seen either because he was stealthy enough to not leave behind any of his own. There's no reason to believe Snake wouldn't have been stealthy enough to do the same
You guys are so fucking hilarious! If I have the amount of subscribers necessary, I will react to some Death Battle videos myself! I fricking think you two should be special guests on my channel! I'll even include you two in my next Wattpad fanfiction! You're welcome!