Yeah, if his arms still bend enough so that his hands can reach his hair and his face, then you're probably fine! 
Also, you probably already know this, but make sure not to leave Pullips' hands, or anything other than their hair and their neck (lol, no avoiding that), touching their heads because it can cause chemical plastic "melt." I don't know why, but the plastic that Groove has chosen for making Pullip heads is extremely sensitive to chemical melt, so that's one thing we collectors always have to watch out for. (In fact, those of us who rebody our Pullips use teflon tape around their necks to prevent plastic melt.) Just FYI.
Also, you probably already know this, but make sure not to leave Pullips' hands, or anything other than their hair and their neck (lol, no avoiding that), touching their heads because it can cause chemical plastic "melt." I don't know why, but the plastic that Groove has chosen for making Pullip heads is extremely sensitive to chemical melt, so that's one thing we collectors always have to watch out for. (In fact, those of us who rebody our Pullips use teflon tape around their necks to prevent plastic melt.) Just FYI.