~すむことではない => ~ is not enough to solve the problem; cannot be resolved by ~ N1
Emphasize the negative meaning
むき => facing towards N3
Direction
むりをする => to work too hard, to try too hard, to strain oneself N3
Description
むしろ => rather; instead N2
Compare
...はむりだ... => impossible N4
Description
込む => to be crowded N3
なくて済む/ないで済む => get by without doing ~ N2
... こととする => to decide on N2
Speculation
~ことにする      => to decide on N4
Decision
ことにする => to decide on N4
Determined, determined
ずにすむ => Not doing A will suffice; Can get by without doing A N1
Need/Requirements
ことにする => Treat as if... (Handling) N1
Means and methods