To change the 'balance' between multi pads in the same bank, unfortunately you need to edit them at the individual pad level.
In the example in your post, you would need to either lower the overall volume of Pad1 or increase it for Pad4.
You can do this on the keyboard using it's 'Multi Pad Creator' function.
After opening MP Creator, select the pad that you want to change and open the 'Edit' display (which I believe is called 'Step Edit' on Genos) to show the MIDI Event List.
In the list of MIDI events that this page shows, you should look for a volume setting event which will appear as Ctrl 7 in the list. If there is one, it will normally be in the first measure (make sure that you have the event filter set to show all event types!)
If there isn't already a Ctrl 7 event, you can add one by selecting an event (ideally a control event) and inserting a second instance of that event. You can then change the relevant columns of the new event to change it to a Ctrl 7 event.
Now you can adjust the data value associated with this event to change the overall volume of that pad.
Repeat with other pads in the same bank if necessary and save the bank when satisfied.
If you can't create the level that you want with a Ctrl 7 volume event, then you would need to adjust the velocity (volume) data value for each note in the pad individually!
If you need to do this, then depending on the pad, it may be easier to do it using a computer program such as MixMaster, which should allow you to select and adjust all notes by a similar amount in a single operation.
Regards
Ian