driver placement for horizontal mid and tweeter in 3 way design

[sagitis]

I do understand that generally vertical aligment is the best, however due to size restrcition my mid, and tweeter placement will have to be horitonal, so i am looking at some past design reference

https://audio-heritage.jp/DIATONE/diatoneds/ds-3000.html

https://audio-heritage.jp/DIATONE/diatoneds/ds-v9000.html

The question is should I palce my tweeter closer to the centre or far away, the tweeter placement of in the two diatone is slight different, do my ribbon tweeter need to adjust and place slightly higher than than the mid regardless of the vertical position

p.s the speaker is three way mid is atc sm75, croossover frequency should be around 2 to 3khz
.

 

[AllenB]

The tweeter doesn't need to be the highest.