Maybe you are confusing achilles with ACL? Achilles isn't an injury that takes a year before a player is 100%. It's an injury that is called the carreer ender and except for very few exceptions, players even if come back aren't 100%...ever again. Not sure the Pistons would be interested to reunite the brothers when they affect each other very badly. Also the Suns JUST got away from too many problems by using the 3 guard rotation that left everyone unhappy and asking out, and have like 2 other young players at least that need playing time desperately. (goodwin ,booker). Besides the Piston didn't resign Drummond to keep theri capspace for next year to be a player in FA. Markieff takes away that ability.
Aggression and confidence with a worse jump shot is not a good thing lol. Lawson's problem isn't confidence or aggression - he's been a regular at the FT line his whole career. The issue is simply that Harden handles the ball for 35+ minutes a game and Lawson doesn't know what to do for all but 13 minutes of a Houston Rockets game. That same problem would be dramatically worse with Jennings since he can't even hit a shot when he DOES handle the ball.
Going the traditional route at the 1 when Harden handles the ball so much is a mistake. Find a quality combo guard next to James.
Jennings is averaging 35% on 2 made 3's per game for his career. That's pretty damn solid. All Jennings would need to do in Houston is be a spot up jump shooter on the perimeter, which he is effective at doing. In 412 games Jennings has hit 775 threes compared to Lawson in 442 games hitting only 418. Lawson may average 1.5% higher career average from 3, but if you factor in volume its clear that Jennings is a better 3 point shooter. You will also be surprised by Jennings passing. Lawson career assist average is 6.5 with 2.2 turnover, Jenning's is 6.2 with 2.4 turnovers. So while Lawson is better, Jennings isn't that far behind, he's a good passer with a really solid assist to turnover ratio.
I agree Harden handles the ball too much but if you think Lawson isn't aggressive enough or doesn't lack confidence out there I don't know what to tell you!