"Using existing technology is also Ares case! SRBs ! Project Jupiter will use shuttle technology, but not exactly with the same characteristics; engines (not SSME's) below the ET, not to its side like the shuttle. If the slightest thing is changed, many things must be retried and that's what they find with Ares. "

You just made the case for Jupiter. Look at the pictures on page 11 of the PDF.

It clearly shows that ARES is growing the ET in length and width, Jup uses the std tank.

Ares requires a NEW 5 segment SRB, Jup uses the existing SRB.

ARES requires two NEW and DIFFERENT upper stages. Jup uses the modern, reduced complexity J2XD upper stage engines, the SAME upper stage for both Jup configurations.

Jup reuses current Delta IV main engines in the 1st stage.

Jupiter's 1st vehicle the Jupiter 120 seriously outperformes the ARES 1 "stick" the one with POGO and weight problems.

"In direct contrast to the current Ares Launch System (ALS), the Jupiter Launch System (JLS) reuses most of the existing manufacturing, integration and launch facilities of STS, as illustrated in figure 2. Because all the new technology requirements are moved to the lunar exploration phase of the VSE, NASA can focus initially on fielding a significantly safer launch system than the Space Shuttle, yet one which is far more capable than the Ares-I. With
more than double the lift capability of Ares-I, the first Jupiter Launch System (JLS) variant enables the Crew Exploration Vehicle (CEV) development team to deliver a fully lunar-capable vehicle to NASA, unconstrained by the current limitations of the Ares-I. In addition, this first variant of the JLS, the Jupiter-120, has enough excess capacity to complete the ISS, thus obviating the painful decision of leaving finished ISS elements on the ground or
retiring the Space Shuttle on schedule."

What's not to like about this approach? Unless of course you're an advocate of NASA as a jobs for aerospace contractors agency. No wonder NASA management doesn't want ARES problems exposed via design review.