Hi Kunjan,
I hope i have not mis understood you but here's my understanding.
In lay man Terms UL = Image if 12th House and A7 is image of 7 th house. So these two independent reflections may or may not fall in the Same House. As in your quoted example they happen to fall in same house, which does not mean they are one and same.
just to stretch your logic--> If there are two planets in a same house does not imply they are one and same. They give their results as per the sign, and relation with each other etc... So is true with UL and A7 in same house.
Also as Swapnil has already mentioned the Arudhas have different aspect and play varied roles.
--> For eg : If UL and A7 are in 2/12 or 6/8 relation then it may indicate problems in marriage based on its physical aspect (also other factors have a say.) or say UL -A7 are in kendra from each other then it benefic to the marriage.
Now if UL and A7 are conjuct (here -just in same house) it does have say, and whats that I'll leave it for your to
explore (extend the logic above). I gave you a small peak into it, apply it and share with us, as this is a learning Forum.
Well my know-how is limited, hence wait for replies from other learned members. In meant time just google 'Arudha' or on scribd.com you'l find loads of info.
I hope it helps
warmly
Asro