‘Breach, violation or non-performance’ is just an example of the kind of problem encountered by translators working out of English. I have met native speakers of German who prefer to work into English largely to avoid this problem of contract translation.
What do the doublets or triplets mean? Probably the lawyer who drafted the contract wasn’t sure but used an established phrase.
How can you find out if they are synonyms or not?
Books on using plain language in the law can be helpful, because they sometimes say which doublets are synonyms and which aren’t. For instance, Mellinkoff, Legal Writing: Sense and Nonsense has an appendix B which lists coupled synonyms.
acknowledge and confess
act and deed
annual (sorry, should read ‘annul’)and set aside
authorize and empower
conjecture and surmise
covenant and gree (should read ‘agree’)
and many more.
The problem is mentioned by Enrique Alcaraz and Brian Hughes in Legal Translation Explained:
There is, of course, the possibility that the original phrase contains a mere tautology exhibiting neither subtlety nor rhetorical aptness, i.e. what is sometimes called ‘a distinction without a difference’. If this is the translator’s conclusion, there would seem to be two options open: silent simplification by dropping the less general term, or simple reproduction. Lawyers, after all, are not always breathtakingly compelling speakers or writers, and it is likely that most languages would tolerate literal renderings of rather weak pairings like ‘final and conclusive’, even if conscious stylists would not applaud them. On the other hand, the doublet ‘alter and change’ is a candidate for simplification to the equivalent of ‘alter’ or, alternatively, to some such treatment as ‘alter in any way’.
The problem is also addressed in this paper:
Exploring near-synonymous terms in legal language. A corpus-based, phraseological perspective
This paper aims to determine the extent to which a corpus-based, phraseological approach can be effectively applied to discriminate
among near-synonymous, semantically-related terms which often prove troublesome when translating legal texts. Based on a substantial multigenre
corpus of American legal texts, this study examines the collocational patterns of four legal terms ‘breach’, ‘contravention’, ‘infringement’ and ‘violation’, first in the genre of contracts and then in the multi-genre context of the entire corpus. The findings highlight the
area of overlap as well as specificity in the usage of these terms. While collocational constraints can be argued to play an important
disambiguating role in the semantic and functional analysis of both source and target text items carried out by translators prior to the
interlingual translation, this study emphasizes the applicability of the phraseological approach to English source texts.
I’ve long been tempted by the idea that computer study of collocations could help translation problems. But I’m not really sure. At all events, the author see this study as merely the beginning of an approach to analysing legal synonyms and near-synonyms.
The collocational information can be treated as a clue or a prompt to evoke a generic scenario in which a particular legal concept functions. Such is the case of breach, which reflects a unity of domain and genre with a well-defined and homogenous class of objects this term refers to. Similarly, the use of infringement is marked by domain-specificity. This tendency for certain legal terms to co-occur with other terms or phrases marked by semantic resemblance could also be accounted for by referring to the concept of semantic preference (Stubbs, 2001). In contrast, violation cuts across legal domains and genres and it is the most ‘inclusive’ of all the terms. Finally, contravention illustrates a heavy phraseological restriction to virtually one form of (a) phrase.