We're all going to see things a bit differently. That's just how it goes.
I can't get myself to call
MARS and
MOON 4th house planets in Bundy's chart. I've come to find the 5-degree rule to be too arbitrary ? handy for making astrological life easier, but simplistic. Moon is just minutes away from the 5th house by the rule. Mars is 9.5 degrees from the 5th ? and a long 27 degrees from the 4th house cusp. Both are in Sagittarius, the 5th sign from the ASC. So . . .
if you're leading up to Mars as the dominant 4th house planet because it rules 4th cusp Scorpio ? well, here is my protest in advance.

Mars is too 'off to the side' for 4th house matters, in my opinion, and is busying himself in 5th house affairs.
About that Sagittarius
SUN: Yes, using Placidus houses I would call that a 4th house planet because it's deeply situated within the 4th, not too terribly far from the cusp. As ASC ruler, the Sun might be the most dominant planet in the 4th. But I've been permanently damaged through exposure to whole sign houses and find its position in Sagittarius to be a weakening influence regarding 4th house issues in this chart (but I confess to not being sure I should be thinking that).
I'm tempted to call
JUPITER the dominant 4th house planet. It's conjunct the IC, within the same sign as the IC degree. It's the chart almuten and has influence through such factors as being the domicile, triplicity, and term lord of the ASC-ruling Sun, the domicile and triplicity lord of the Moon, the domicile and triplicity lord of 4th house-ruling Mars, the triplicity lord of the ASC degree, and the domicile, triplicity, and term lord of the pre-natal syzygy Moon. Jupiter rules the 5th house of pleasure and sex, and the 8th house of death. The 4th house itself has associations with death, and there's Jupiter conjunct the cusp in that dark murky sign of Scorpio. Jupiter is strongly placed oriental of the Sun and is breaking free from combustion, beginning a new phase cycle. This is a Jupiter that wants to do things.