Im in a cyclone( hurricane) and flood area, also exmilitary and work remote sites. All I use is a fenix E01 on a keyring, convoy C8 gunlight, Fenix Hl23 AA headlamp, and Nitecore EC4GT flashlight
In military/tactical terms if it helps, or just for general knowledge the levels of equipment carry are
1. Duty wear/patrol order. this is basically your duty belt and daypack, or in the military, chest rig/harness etc. With this you will hae your firearm, abou 200-300rounds ammo, 24 hours emergency rations and water, comms gear, utility knife, short rope, firemaking gear, EDC flashlight and possible an emergency blanket are the sort of things in this gear. its designed to allow you perform your duties, include fight short term or live for 24 hours in the field. This equates to a 30-40 litre daypack of stuff in a civilian context
2. Marching order/Field pack/main pack. 70-100litres. This is basically your house on your back, everything else you need to survive in the field. Sleeping bag, matt, shelter, change of clothes, cooksets, eating gear, specialised equipment, food up to 7 days but possibly 14 days etc. extra batteries and extended operation supplies. Soldiers march into location with their field pack, usually drop it to patrol from that location or fight just wearing their patrol rig( above). Marching order equates to a large backpack for hiking etc.
3. listed last to outline setups to survive 48-72 hours. Packs between 50-60 litres, various config and between the other two main types.
Generally my take on a bugout bag depends on needs but will sit between type 1 and the in between stuff. Whatever size pack suits you needs.
My config is to have all flashlights always available in option 1.(which is added to no.2 if I am going to the field) .So for me that is the gunlight(c8), EDC(EC4GT), headlamp and little fenix keyring light. This gives me two items running off 18650 , 1 off AA and 1 AAA.
Are these all needed, of course not...most of the time. The gunlight can go if Im not taking the gun for a start. So its basicallty the EC4GT and the headlamp. (The Fenix AAA keychain light I dont even really count as its so small)
For the record I know people purely in an ultralight civilian hiking context taking the smallest light they can, often a plastic AAA or AA light to keep weight down. I see two lights as a better idea though.
Take my military advice as general interest. A military set up is not the be or end all or even the best setup for a lot of situations. When I was doing a partiuclar job in Africa our bugout bag( or grab bag as we called it) was much smaller than a normal patrol order setup or evern my flood/hurricane bugout bag here. For the simple reason we were not wearing military order and needed a very small bag under 10 litres with vital gear like cards, passport, 1 change of clothes, meds and a water bottle. Reason being if we were suddenly evacced from the workplace the aircraft had very limited space requirements.