You see, Occam's Razor is a counter I can be contented with.
While half strength meaning half force is an obvious interpretation, my interpretation relies on the chance that "strength" is being used in a technical sense for "efficiency in battle", which is still a greater assumption than taking the statement at face value.
However, to counter the plain obvious, I brought up logical issues with it, to even the playing field. Chopper referring to Bazooka as Oars' strength, a move Oars used a singular time in the battle before then doesn't make sense, Oars relies exclusively on Gatling or singular limb attacks. And Oars' is strong enough to heavily damage the crew with said single linb attacks, making Chopper's statement effectively useless from a narrative standpoint.
If the statement refers to both bazooka and gatling attacks, like KT said, then it's more of a support that "strength" is referring to arsenal, rather than brute force.
I believe these factors, alongside with Chopper maybe not being the most reliable source (Knowing anatomy doesn't mean you know the physics behind punches/kicks, and wouldn't make sense to use Chopper's anatomy knowledge if you're just applying it to Luffy) are enough to make the statement itself dubious, and turning it unreliable enough to not be used.
With that said, I admit it's not a full blown debunk, I wouldn't complain if the multiplier only applied to Luffy and Oars.