なくて済む/ないで済む => get by without doing ~ N2
を[経「へ」]て => After A N1
Time, Situation
合う => do something together N3
~をたて(~を経て)      => through; after; via N1
ずに済む => get by without doing ~ N2
... 反対に => on the contrary N3
Compare
~こと請け合い => I guarantee ... N1
Happens next
て済む => sufficient by; no problem to; resolve by ~ N3
[合「あ」]う => To do A together/mutually N4
Secondary Verb
に対して => towards; against; regarding; in contrast with ~​ N3
場合(は) => in the event of; in the case that ~ N4
のに対して => towards; against; regarding; in contrast with ~ N2