You can check these for inspiration on what HKs ppls use:
- [aM']Hearttt https://aokhotkeys.appspot.com/presets/get/5055910950993920
- VIK_Vinchester (personal favorite) https://aokhotkeys.appspot.com/presets/get/5150297152290816
- [TyRanT]RiuT https://aokhotkeys.appspot.com/presets/get/5204403183157248
- [TyRanT]slam https://aokhotkeys.appspot.com/presets/get/5974448482025472
- [TyRanT]BacT https://aokhotkeys.appspot.com/presets/get/5691202112323584
- [_sT]Spring https://aokhotkeys.appspot.com/presets/get/173611014
- [TyRanT]TheViper (outdated btw, but can get ideas) https://aokhotkeys.appspot.com/presets/get/26006
- [TyRanT]TaToH https://aokhotkeys.appspot.com/presets/get/5810997407252480
The ones that are most important for micro only (in order) are imo Flank+Normal stances (these are important to be in a shape of easy access, many have A+F or Q+F, to be used with Ring and Index finger), Staggered Stance, Ground Attack, Stop and Stand Ground. That'd be 6 most important, when taken into account that Stances affect military units, which are more numerous than Siege units which require Ground Attack (~mangos) and thus have more priority in a combined list. Note that you'll get them down to 5 when you think Unit-only, and AGround would only be used when only mangonel/treb was selected, so it can overlap with some keys not relevant to that context.
Defensive Stance is less important since you would micro eg. feudal spears vs scouts anyways every time they attack, in order to try get hits in.
Go-To Last Notification is useful in a limited fashion, imo, depends on how you're used to reacting to alerts, and very situational so it's not a priority (I for one look/click at minimap if necessary, and also can choose not to click if I see enemy is eg. attacking a walled section as a distraction, so I can make a split-second decision whether it's a distraction or not, worth checking).