I'm glad you have usable results, but for future reference I recommend you always use ground control.
(Even those of you that have an RTK/PPK drone, ground control is not technically NEEDED, but we still recommend using measured points as Check points - withheld from the aerotriangulation - to verify accuracy).
If you don't have accurately surveyed points, you can extract points from the Esri imagery basemap, and that will include Z values from the ArcGIS Online world terrain to ensure you get the proper Z values. Two caveats with using control from the Esri basemaps:
Our basemaps are compiled from multiple sources, and we cannot provide an accuracy statement for the horizontal positions. The same is true for the DEMs used to compile the world terrain, so it's generally good everywhere but we do sometimes discover errors in the DEMs - sometimes very localized - so multiple points and careful QC are still recommended.
Cody B.