Default settings for Frogger is all dip switches in the 'On' position, which will give you 3 frogs to start. TG settings is 5 frogs to start (dip#2 = Off).
Don't read too much into what TG says is "right." Even when their tracks specify settings and say it is the manufacturer default that is not always the case. Always check the game's manual. Unfortunately, many times manufacturers did not specify what the settings were by default from the factory, but I've found that what is usually the case is that on the dip switch block of eight switches the first seven are set the same and the last one is reversed, and usually the last dip is the one that specifies if the board is in an Upright or a Cocktail (affects screen orientation and/or flipping).
In Frogger's case, dips 1 and 2 'On' give you 3 frogs, dip 3 'On' specifies Upright cabinet, dips 4 and 5 'On' specify 1 coin / 1 play, and dip 6 is unused.
Also, TG switched to 5-man start on many games back in the '80s when they were promoting Twin Galaxies Tournament Settings (TGTS) in an effort to discourage marathons. The idea was to limit (or eliminate if possible) extra men awarded and set the game to 5-man start or as close to it as the game settings would allow.