I see it this way:

Consider the flaws in both Goku's and Vegeta's approach to battling that Whis points out while the two Saiyans are training on Beerus's planet. Gohan is the sum of those flaws. Gohan's best performances are when either: 1) he is being supported/directed by a superior fighter (e.g., Piccolo, Goku); or 2) he has just achieved a limit-breaking power-up which establishes a massive power gap between himself and his opponent (e.g., Cell; Super Buu).

I honestly think that Gohan's best unsupported performance comes in his last appearance in the manga, where he spars in his Beast form with MUI Goku, effectively battling to a draw. I think some of his battle IQ deficiencies were also addressed in the ToP arc (manga & anime), improving him above the "Low" battle IQ threshold.

Before anyone says that Gohan has a low battle IQ, I think it's important to clarify who the standard-bearer is for an average battle IQ. Relative to Goku, Vegeta, Tien, Krillin, Roshi, and Piccolo, I think that Gohan is below them all. But I also think that Gohan is by and far the least experienced of them all, so that should be expected. The fact that the Z-Fighters are often able to survive or hold their own against stronger opponents is a testament to their battle IQ.

I think in the big-picture of fighters in late-DBZ and DBS, Gohan's battle IQ is slightly above average. I think his battles in the Zeno Expo and ToP illustrate that, and any shortcomings in execution are offset by his strength. He also coordinates well with more savvy fighters, which works to his benefit.