In first case you are talking about Scorpio Lagna... where 5th Lord Jupiter has gone to the 3rd house debilitated and 3rd Lord Saturn is in the 5th house.. as mentioned by sir that exchange is always appreciated. this exchange will give strength to Jupiter, which is good as Jupiter is a karak planet..on the top your education and your inclination/ skills are correlated now or you can travel for attaining education or your kids will have high Aspirations in life. practically such cases can be experienced.

Second case let's take an example that Jupiter is in the sign of Sagittarius in the ninth house and goes to the 8th house in Bhava chalit.this can happen in Aries Lagna...it would have been better if Jupiter was in the 9th only but still Jupiter is in its own sign and if makes relationship with benefic planets it's still ok.

Actually in both the cases Jupiter has different kind of strength and each strength has his own meaning. in the first case Jupiter is debli but close to dig bal and has exchanged signs; in second case Jupiter has strength of own Rashi.