Photo order ( not in an album or folder)

You have very limited choice.

The only option that you have is sync your Mac/PC Photos to your iPhone using iTunes. That way the Metadata will not get changed and your photos will remain organised as you want it. Do remember that, this is not an import, this is Sync; that means if you delete the photo in one it is deleted in the other.

Second option is, though I have not tried it but there are few third party apps that may do this import for you.

Photos

Enjoy a curated view of your best moments in the Photos tab and browse by Years, Months, Days, or All Photos for your complete library. See Live Photos and videos come to life as you scroll and browse. 

• Years: View your entire library of all the photos and videos that you've taken each year. Swipe to scan some of the highlights.
• Months: See groups of photos and videos taken during each month by memories and locations. Tap  to share or play a movie created from your favorite moments.
• Days: Browse your best photos of the day and watch some of your videos automatically play as you scroll. Tap a photo and swipe up to see its location on a map, and the people in it. 
• All Photos: See your complete photo library including screenshots and duplicate photos in the order they were taken.

Live Photos and videos won't autoplay in Photos when Low Power Mode is enabled. 

Meta data of a Photos cannot be changed on an iPhone. Did you import the Photos to Mac or PC earlier and transferred it back to iPhone through AirDrop?