In Longman Dictionary, under 'over against something', it says that
• over against something (UK) = in preference to
Then, how can I use the phrase 'over against' in sentences?
When it is not used in a locative phrase but figuratively, it often has the meaning "compared to" or "relative to".
In this scheme, local state governments are given greater power over against the central authority.
In bankruptcy law the fees owed the bankruptcy lawyers are privileged over against moneys owed to vendors and suppliers.
There are usually better ways of stating the thing over against "over against".