If you look carefully you will note that throughout the play there are many references to Bob Acres being small of stature.

It is probably no coincidence that the actor who first played this role, John Quick, was also a small man( seen here as protrayed by Gainsborough Dupont>

In The Children of Thespis written by Anthony Pasquin, a poem about 18th century actors, Mr Quick is described as

A Tiny ,Blithe Dwarf

Keep a look out for these mentions( there are two more for you to find in the forthcoming scenes) for I think the add to the jokes as intended by Sheriden .

On to another point.

In Scene iv of Act III, Sir Lucius says:

What the devil signifies right, when your honour is concerned? Do you think Achilles, or my little Alexander the Great, ever inquired where the right lay? No, by my soul, they drew their broad- swords, and left the lazy sons of peace to settle the justice of it

and Acres replies:

. Your words are a grenadier’s march to my heart! I believe courage must be catching! I certainly do feel a kind of valour rising as it were—a kind of courage, as I may say.—Odds flints, pans, and triggers! I’ll challenge him directly.

Acres is possibly reminded of the marching song The British Grenadiers by Sir lucius's mentioens of Alenxander and Achilles..

Here below are the accepted lyrics of the marching song: but Lewis Winstock in his book The Songs and Music of the Redcoats(1970) has found that one contemporary version of that song began

Some talk of Alexander and some of Achilles

not Hercules, which makes sense ,and explains this passage.

Some Talk of Alexander and some of Hercules
Of Hector and Lysander and such great names as these
But of all the world's great heroes, there's none that can compare?With a tow, row, row, row, row, row, To the British Grenadier.