Using the Range function with the Slot (#) function

Clear["Global`*"]

nRow = 10;

nCol = 25;

l = {Blue, 
     Disk[{3 Sin[5 t + 0.1 #[[1]]] + 1.4 #[[1]], 1.5 #[[2]]}, 
      0.5]} & /@ Flatten[Array[{#1, #2} &, {nCol, nRow}], 1];

Animate[Evaluate[Graphics[l, PlotRange -> {{-4, 44}, All}]], {t, 0, 
  20. π}, AnimationRate -> .3]

Array:

ClearAll[disks]
disks[t_, nc_, nr_] := Array[Disk[{3 Sin[5 t + 0.1 #] + 1.4 #, 1.5 #2}, 0.5] &, {nc, nr}];

Animate[Graphics[{Blue, disks[t, 25, 10]}, PlotRange -> {{-4, 44}, All}], {t, 0, 20.  π}, 
 AnimationRate -> .3]

Outer:

ClearAll[disks2]
disks2[t_, nc_, nr_] := Outer[Disk[{3 Sin[5 t + 0.1 #] + 1.4 #, 1.5 #2}, 0.5] &, 
 Range @ nc, Range @ nr];

Animate[Graphics[{Blue, disks2[t, 25, 10]}, PlotRange -> {{-4, 44}, All}], {t, 0, 20.  π}, 
 AnimationRate -> .3]

same picture

Tuples:

ClearAll[disks3]
disks3[t_, nc_, nr_] := Disk[{3 Sin[5 t + 0.1 #] + 1.4 #, 1.5 #2}, 0.5] & @@@ 
  Tuples[Range /@ {nc, nr}];

Animate[Graphics[{Blue, disks3[t, 25, 10]}, PlotRange -> {{-4, 44}, All}], {t, 0, 20. π}, 
 AnimationRate -> .3]

same picture

ClearAll[disks4]
disks4[t_, nc_, nr_] := Disk[#, .5] & /@ 
  Tuples[{3 Sin[5 t + 0.1 Range[nc]] + 1.4 Range[nc], 1.5 Range[nr]}]

Animate[Graphics[{Blue, disks4[t, 25, 10]}, PlotRange -> {{-4, 44}, All}], {t, 0, 20. π}, 
 AnimationRate -> .3]

same picture