The Specs of both Schneider and Rodenstock do specify that a 135mm el-lens covers 9x12cm (the european conterpart to 4x5"). Although their specs are usually conservative, they do not leave you much tolerances in practice. So you may find it difficult to exactly center a 4x5 in your 5x7 carrier.
Light fall-off might is not necessarily a bad thing. You may even use it consciously to compensate light fall-off of a super wide camera lens.
BTW: the 180mm lenses officially do cover 13x18cm (which equals 5x7" quite exactly) - so it's not really the same situation here