Grouped objects and focus order

Another focus order question from me:

I have a word and an image that I have grouped together, the trigger is show layer when the user clicks group 1.

My question:  In the focus order I see for example:  Infective agents Group 1, Infective Agents Text Box 1 Bacteria, Infective Agents Bacteria Picture.  In the focus order because the trigger is attached to Group 1 do I just keep Group 1 item and delete the Text and Picture and use alt text to say "Select to learn more about bacteria?  Or should I not trigger from a group and perhaps just the picture, than keep the pic and text and delete the group?

Hope that makes sense?