ffmpeg
-i video_and_audio.ts
-i audioOnly1.ts
-i audioOnly2.ts
-i audioOnly3.ts   //four inputs
-y

-filter_complex
[0:a]aformat=sample_fmts=fltp[mid0]; //get just the audio from the first input (the video+audio)
[mid0]adelay=1[nar];            //start 1st input's audio at 1 millsecond...

[1:a]aformat=sample_fmts=fltp[mid1]; //get audio from 2nd input
[mid1]adelay=1[aud1];       //start 2nd input at 1 millisecond...

[2:a]aformat=sample_fmts=fltp[mid2];//get audio from 3rd input
[mid2]adelay=1745300[aud2];//start 3rd input at 175...

[3:a]aformat=sample_fmts=fltp[mid3];//get audio from 4th input
[mid3]adelay=1758700[aud3]; //start 4th input at 175...

[nar][aud1][aud2][aud3]amix=4[out]  //mix all 4 pieces

-map 0:v -map [out] //take 0 stream's video, and filter's output

-profile:v main
-level 3.1
-movflags +faststart
-c:a aac
-b:a 64K
-f mp4
output.mp4