Nub Fire Emblem: Shadow Dragon question

Because I don't feel like making a Gamefaqs account. Last thing I need is getting sucked into a forum full of insanity and fail.

For this game, there's no Constitution which was used before to determine if you will be penalized to equip a heavy weapon, and according to the FE wiki it says attack speed is affected by Strength now. Does that mean Strength is what will let a character double attack, or is it still Speed? If it's still speed, then is Strength the new Constitution or some arbitrary factor?

If str is used in place, where I don't see any other stats that could be, and it's supported by the fact that all tomes are very light in this game, then the formula would be.

Speed - (weight - str) = speed stat used in calcs where Weight > Str, otherwise just uses speed.