Full Idea
'Bob and John play golf' and 'John and Bob play golf' are equivalent; but if they were to be derived from the same underlying structure, one or the other of Bob and John would have to come first; and either possibility is arbitrary.
Gist of Idea
Sentences are different from propositions, since two sentences can express one proposition
Source
Gilbert Harman (Thought [1973], 6.4)
Book Reference
Harman,Gilbert: 'Thought' [Princeton 1977], p.94
A Reaction
If I watch Bob and John play golf, neither of them 'comes first'. A proposition about them need not involve 'coming first'. Only if you insist on formulating a sentence must you decide on that.