The grant comparisons don't really make any sense, just completely different kinds of players.
They are about the same height (6'6 w/o shoes), but Walsh is longer both standing reach (8'11 vs 8'8.5) and wingspan (7'2 vs 6'10) while also being more athletic. Grant has his weight/strength wise, has about 30 pounds on him. Grant had way more offensive game right away than Walsh does who really is strictly a transition/cutting guy right now.
The best comparison for Walsh might be somebody like Herb Jones. 6'6 w/o shoes, 8'10 standing 7'0.5 wingspan same weight. Wlash is even a little longer and Jones was a senior out of the draft so its not a perfect comparison, but it terms of what you want them to do Walsh could make a similar impact if he can shoot just okay like Herb (get up to 33-34% and he's a rotation guy).
They make sense when you think about role. They will be tasked with similar defensive assignments. Walsh’s offense will hopefully progress to “make open threes in the corner”. Sure, Walsh is longer, and Grant was a more accompanied scorer coming out of college, but when you consider what roles they have had/will hopefully have on the Celtics, they’re fine comps. Are there better comps on other teams? Probably, but that wasn’t the point.
See I don't think their roles defensively are actually all that similar. Grant was mostly used as a 4 or small ball five and guarded bigger guys like Giannis, Embiid, Siakam, and Bam sometimes. He was basically a 6'6 center defensively and struggled at times with smaller guys off the bounce.
Walsh by comparison is going to be more like a 1-4 defender who's probably best on primary ball handlers due to his length and ability to move his feet, but I'm not sure he's going to be a guy you put on Giannis, Embiid or centers much because he's a little light in the weight department. Maybe in a few years when he ass his early 20's muscles.
Those are very different roles to me. And that's fine! The C's picked up another center, but lost a switchable wing player in Smart to do so. Walsh is almost more like Smart defensively than Grant (I am not, in any way, saying he will be as god a defender as Smart, especially as a rookie. Smart was a generational perimeter defender. Just saying he's more that TYPE of defender i think in that he is versatile).
On offense same thing. Grant was a spot up shooter, not really much of an at rim finisher. I hope Walsh can figure out the shot but I could almost see him playing more like a rim running center early on as he seems to have a feel for cutting and offensive rebounds.
