I'm kinda having confusion on how David Keirsey defines SP temperament on wishing to make an impact on others. The way I see it is that all temperaments have that desire. I think either S or N temperaments could want to make an impact, particularly if Extraverted, but they just do it in different ways.
S will probably want to impact/entertain others through the use of physical, concrete action (i.e. sports, dancing, talking about their experiences). My thought is that S takes more pride in craftiness. They'd rather be seen not as imaginative, but as skillful in what they do.
N will probably want to impact/entertain others with their fanciful ideas (through telling fictional stories, creating imaginative artwork, or coming up with a new way of doing things). My thought is that N takes more pride in their creative ideas. They'd like to be seen by others not as skillful, but more imaginative.
Also, I think in this case, being practical or meaningful has more to do with the T or F preference.
I think that regardless of your S or N preference, I think the T function will emphasize practicality and usefulness. Examples: an ENTP will look to see how their conceptions would be applied, possibly making them good inventors. The ESTP will more likely notice practical opportunities as they come up.
If your preference is F, then I would think, regardless of an S or N preference, both types would likely wish to entertain. ENFP will entertain with imaginative ideas, while ESFP will entertain through physical action.
Am I getting this right?