Attach Image in Mail instead of Embed

Are you concerned that the images are referenced in the middle of the mail message and are not at the end?

That's how the message was generated.

Or are you concerned that some of the attachments are viewed as images, and some are little blobs with a filename?

That's some rendering that Mail.app does, to make it possible to view (short) attachments in-line.

Underneath? The MIME-encoding used by Mail.app works exactly the same way with all attachments.

Does Mail.app > File > Save Attachments do what you want?

If you don't want to control-click on the images and select the View as Icon for each, and prefer the file icons and not the rendering... But that doesn't change what's happening underneath here, and the MIME-encoded mail messages are exactly the same.

In the messages that you're sending, there's no difference between what you're calling "inline" and "attached". Mail.app shows attachments as icons if requested—control-click and select View As Icon—but does default to showing the contents for various types of common attachments. They're all standard MIME-encoded email attachments, and it all works the same way underneath, no matter how Mail.app might be showing the attachments; whether as icons, or as the contents of the particular attachment.