I don't really get where he says Base Offense is the strongest offense. It's clear in the GE that the best offense is solely dependent on your personnel. And not by being flawed either.
I think the concept is something like that every other tactic adds a bonus to some part of your offense, but has a bigger drawback. For example (with completely made up numbers), maybe with Motion you get a 15% bonus to outside shooting and a 20% penalty to inside shooting. So, technically it's a weaker offense because it has more in penalties than in bonuses.
Of course, if you then factor in your team, though, if you have strong outside offense and practically zero inside attack, the 20% is of almost nothing while the 15% is a major upgrade, in which case that improves your overall ratings and performance quite a bit.
The best way of thinking about it is that Base Offense is always the strongest offense, unless something else is. ;)