My take on it is that distance was an issue when the father's days off coincided with school days and yes if it were not 4 days but 5 (M-F) then it would have made a difference.
I'm not sure if your caravan analogy helps much as that is not ideal accomodation and from numerous cases there appears to be a consistent desire of the Court for the children to at least have their own room to sleep in.  
The conflict between the parents becomes an issue often where the lack of will to try work things out often results in the Court being forced to pick one or the other or at least weigh all factors with that in mind.  
In Mazorski v Albright [2007] FamCA 520; (2007) 37 Fam LR 518 Brown J at paragraph 26 described a meaningful relationship as one “which is important, significant and valuable to the child”, observing that the word meaningful is “a qualitative adjective, not strictly a quantitative one”. This is consistent with the definition of “significant and meaningful time” in s 65DAA of the Act. 
The Full Court in McCall & Clark (2009) FLC 93-405; [2009] FamCAFC 92 agreed with Brown J’s observations as to the nature of a meaningful relationship and considered three possible approaches to s 60CC(2)(a) at paragraph 118 preferring what it described as the prospective approach which requires the court to “consider and weigh the evidence at the date of the hearing and determine how, if it is in the child’s best interests, orders can be framed to ensure the particular child has a meaningful relationship with both parents”.
The Full Court also said at paragraph 119 that depending upon the factual circumstances of the particular case the “present relationship approach”, which involves making findings as to the nature of the child’s relationship with both of the child’s parents as at the date of the hearing, findings which are ultimately reflected in the orders, may also be relevant.