Givony states Topic is 6'7 (without shoes) 203, with a meager 6'5 wingspan. This probably explains why he hasn't fully figured out how to contribute on the defensive end. At 18 years old, he's still figuring out his body, which has to factor in why he's not all that agile, etc.
The NBA quietly posted Zaccharie Richacher's anthro and athletic testing numbers. They are not great. He's almost a tweener. That agility score must mean that he never practices this drill. Surely, he's not that slow a foot. Dalton Knecht is a full second faster. Also, multiple European sites had touted him at 6'10." 6'8.5 without shoes 194.6 lbs 8'11" reach 6'9.5 wingspan 2.97 shuttle 3.08 in sprint 11.57 in the agility 25" vertical 31" with a head of steam