The birth dates of Carl and John George (per Wright 1994) — just four months apart — cannot both be correct if they are really brothers.  Based on the censuses, it's Carl's birthyear that is in error.  And if Carl was born in October, he would have been born in 1793, not 1794.

1.  Marriage Record:

2.  John T. Humphrey.  1991-1998.  Pennsylvania Births.  14 vols.  Self-published, Washington, DC (Broderbund Family Archives: Birth Index: Southeastern PA, 1680-1800, CD-196):

Child	Cathrina Strup?	Margretha Strup	Elisabeth Strup
Birth/Baptism	4 Aug 1775	28 Dec 1777	4 Apr 1780
Location	First Reformed Church	First Reformed Church	First Reformed Church
County	Philadelphia	Philadelphia	Philadelphia
State	Pennsylvania	Pennsylvania	Pennsylvania
Father	Strup Strup?	Henrich Strup	Henrich Strup
Mother	Mrs. Sussanna Strup?	Mrs. Sussanna Strup	Mrs. Sussanna Strup

3.  F. Edward Wright.  1994.  Early Records of the First Reformed Church of Philadelphia. Vol. 1: 1748-1780; Vol. 2, 1781-89.  Family Line Publ., Westminster, MD  (Broderbund CD-166):

MARRIAGES BY THE REV. CASPER WEYBERT, 1763 - 1780... Henry Strup m. Susanna George on November 17, 1774.

BAPTISMS BY THE REV. CASPER WEYBERT, 1774 - 1780... Henry, son of John Grewel and Elizabeth, b. November 16, 1774, bapt. January 1, 1775. Spon: Henry Strup and wife...

BAPTISMS BY THE REV. CASPER WEYBERT, 1774 - 1780... Catharine, daughter of --- Strup and Susanna, b. August 4, 1775, bapt. September 24, 1775.  Spon:  John Georg and Catharine... Margaret, daughter of Henry Strup and Susanna, b. December 28, 1777, bapt. August 30, 1778.  Spon:  Henry Schreiber and Margaret...

BAPTISMS BY THE REV. CASPER WEYBERG, 1781 - 1789... Susanna, daughter of Henry Strup and Susanna, b. Feb. 12, 1782, bapt. March 13, 1782.  Spon: Parents... Maria, daughter of Henry Strub and Susanna, b. Jan. 14, 1785, bapt. March 25, 1785. Spon: The Parents and Catharine Strub... Henry, son of Henry Strup and Susanna, b. Nov. 6, 1787, bapt. Dec. 29, 1787.  Spon: The Parents...

BAPTISMS BY THE REV. HERMAN WINCKHAUS, 1790-1793... John, son of Henry Strup and Susanna, b. March 22, 1791, bapt. May 9, 1791.  Spon: -----...

BAPTISMS BY DR. WILLIAM HENDEL, 1797-1798... John George, son of Henry Strupp and Susanna, b. June 27, 1797, bapt. Aug. 11, 1797.  Spon:  The father... Carl, son of Henry Strub and Susanna, b. Oct. 25, 1797, bapt. Nov. 25, 1797. Spon: Parents...

BURIALS BY THE REV. CASPER WEYBERG, 1781-1785... Elizabeth Strup, age 10 mos., 2 wks., bur. Feb. 19, 1781...

John George and Carl cannot have been born just four months apart if they are brothers.  Based on the censuses, Carl was born in 1793/4, so it appears his record is the incorrect one.  And it may be that the baptismal date is correct, and only the birthyear is wrong.  I can only assume the compiler or the publisher screwed up. 

4.  1790 Census Index/Images (online at Ancestry.com; Image #134 of 142; extracted by Diana Gale Matthiesen):¤•

1790

PA

Phildadelphia Co.

Water Street East Side

Roll M637_9

p. 157

Ln. 12L

Henry Stroop

2-2-5-0-0

These data indicate:

Gender and Type	Age Class	Therefore Born	Individuals Inferred
free white males	16 or over	in or bef. 1774	= Henry (b. 1753) = ?
free white males	15 or under	1774-1790	= ? = Henry Jr. (b. 1787)
free white females	all ages	in or bef. 1790	= Susanna (b. 1753) = Mary (b. 1785) = Susanna (b. 1782) = Margaret (b. 1777) = Catharine (b. 1775)

Have we not identified all their children?

5.  1800

6.  1810 Census Index/Images (online at Ancestry.com; Image #3 of 4; extracted by Diana Gale Matthiesen):

1810

PA

Delaware Co.

Darby Twp.

Roll M252_47

p. 487/823

Ln. 12

Henry Stroop

02001-00101-00

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
2 males	10-15	1794-1800	=
1 male	45 or over	in or bef. 1765	= Henry (b. 1753)
1 female	16-25	1784-1794	=
1 female	45 or over	in or bef. 1765	=

7.  1820 Census Index/Images (online at Ancestry.com; Image #3 of 5; extracted by Diana Gale Matthiesen):¤•

1820

PA

Delaware Co.

Upper Darby Twp.

Roll M33_103

p. 9B

Ln. 6

Henry Stroup

000110-11000-0-100

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	19-25*	1794-1801	= ?
1 male	26-44	1775-1794	= Henry (b. 1787)
1 female	9 or under	1810-1820	= Daughter B
1 female	10-15	1804-1810	= Daughter A
1	person engaged in agriculture
*In the 1820 Census, the third column is age class 16-18 and the fourth column is age class 16-25; therefore, any individual in column three is duplicated in column four.  By subtracting the number in column three from the number in column four, you can create an age class "19-25."

This must be the son, so where is the father?

8.  1830 Census Index/Images (online at Ancestry.com; Image #3 of 14; extracted by Diana Gale Matthiesen):

1830

PA

Delaware Co.

Lower Darby Twp.

Roll M19_150

p. 210

Ln. 13

Henry Stroop

000 000 000 100 - 000 100 001

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	70-79	1750-1760	= Henry (b. 1753)
1 female	15-19	1810-1815	=
1 female	60-69	1760-1770	= Susanna? (b. 1753)

Listed six lines from son, John STROOPES.

9.  Archives of the PANORTHA-L Mailing List (online at RootsWeb.com):

Stroop, Henry, Cont. Line (PA) applied in 1818 Delaware County, PA. In 1820 soldier was aged 68 with a wife aged about 65 and a granddaugthter aged 8 living with soldier and he had 7 children of age and away from home, a son Charles Stroop signed p.o.a. in Gloucester, NJ in 1850 as heir of deceased soldier. Soldier had married Susanna George on Nov 14 1774 at Phila, PA

No source is given.

10.  Frank F. Bell II.  1960.  BELL-SHARPE: containing Genealogical and Some Biographical Sketches and Illustrations on … Allied Families to BELL: ATTMORE, EDWARDS, GEORGE, SAUSSAT, RAKESTRAW, STROOP, STULL, ZANE… Unpublished typescript, Dallas, TX (online at HeritageQuest at Genealogy.com).  See excerpt.