For what it's worth, Hoopshype did a survey of NBA front offices in the offseason and had them rate publicly-available advanced stat metrics. There were four metrics that were used by one or more front offices as their primary go-to metric: RAPTOR, LEBRON, EPM, and, DPM. Tatum ranked 6th, 8th, 10th, and 11th in those four, respectively. However, DPM uses a lot of past performance in its ranking (which is probably why it's the most trusted in the NBA because it is less subject to the effects of small sample-size), but that means that it has Kawhi, who hasn't played this season and is likely out all year, ranks ahead of Tatum based on past performance. So of players who've seen at least one minute of action this year, Tatum was top-10 in all 4. There were 19 players in the top ten of at least one of these metrics (excluding the injured Kawhi), but Tatum was one of only 5 to make the top-10 in all four.
In other words, analytics would give a pretty resounding yes that Tatum is top-10, but probably not top 5.
Note: I used the per-minute values for all of these rankings at whatever default minutes a particular stat used. But Tatum has also played a ton of minutes, and scores even higher when you use a total wins version of these stats, rather than something which is minutes or possessions-adjusted. He's top 5 in the three stats (Raptor, LEBRON, and EPM) that offer this calculation.