Body Slam is so good that even with Lick it makes for a great defensive moveset imo. After the first few seconds it just starts spamming Body Slams to death anyway, and those are really, really difficult to dodge even for the most expert players.
I know from first hand experience, since my biggest maxed out Snorlax has L+BS and he does his job superbly. Plus it's a legacy move now, and yours even has amazing IV, so it's a no brainer for me - power him up.