is it worth training a goalie+defender in Offensive skills and attackers in defensive

[ParshulXXL]

I do the same, I train def+mental for defenders and goalkeepers and Att+mental for strikers, while for midfielders I keep them around the same values, so the MC's are just as useful with red or blue arrows. But I also have a set of skills I train without regard to this rule. I train my attackers in heading, I'm not sure it has any effect, but just in case, and I also train my defenders in passing.