4.  Equites fugientibus hostibus occurrunt, the horsemen meet the
  fleeing enemy.

  5.  Galba copiis filium praefecit, Galba put his son in command of
  the troops.

In each sentence there is a dative, and in each a verb combined with a preposition.  In no case would the simple verb take the dative.

426. RULE.  Dative with Compounds. Some verbs compounded with /ad\, /ante\, /con\, /de\, /in\, /inter\, /ob\, /post\, /prae\, /pro\, /sub\, /super\, admit the dative of the indirect object.  Transitive compounds may take both an accusative and a dative.

NOTE 1.  Among such verbs are[1]

  ad’fero, adfer’re, at’tuli, adla’tus, bring to; report
  ad’sum, ades’se, ad’fui, adfutu’rus, assist; be present
  de’fero, defer’re, de’tuli, delatus, report; grant, confer
  de’sum, dees’se, de’fui,——­, be wanting, be lacking
  in’fero, infer’re, in’tuli, inla’tus, bring against, bring upon
  inter’sum, interes’se, inter’fui, interfutu’rus, take part in
  occur’ro, occur’rere, occur’ri, occur’sus, run against, meet
  praefi’cio, praefi’cere, praefe’ci, praefec’tus, appoint over,
    place in command of
  prae’sum, praees’se, prae’fui, ——­, be over, be in command

    [Footnote 1:  But the accusative with ad\ or in\ is used with some
    of these, when the idea of motion to or against is strong.]

427. IDIOMS

  graviter or moleste ferre, to be annoyed at, to be indignant at,
    followed by the accusative and infinitive
  se conferre ad or in, with the accusative,
    to betake one’s self to
  alicui bellum inferre, to make war upon some one
  pedem referre, to retreat (lit. to bear back the foot)

428. EXERCISES

I. 1.  Fer, ferent, ut ferant, ferunt. 2.  Ferte, ut ferrent, tulisse, tulerant. 3.  Tulimus, ferens, latus esse, ferre. 4.  Cum navigia insulae adpropinquarent, barbari terrore commoti pedem referre conati sunt. 5.  Galli moleste ferebant Romanos agros vastare. 6.  Caesar sociis imperavit ne finitimis suis bellum inferrent. 7.  Exploratores, qui Caesari occurrerunt, dixerunt exercitum hostium vulneribus defessum sese in alium locum contulisse. 8.  Hostes sciebant Romanos frumento egere et hanc rem Caesari summum periculum adlaturam esse. 9.  Impedimentis in unum locum conlatis, aliqui militum flumen quod non longe aberat transierunt. 10.  Hos rex hortatus est ut oraculum adirent et res auditas ad se referrent. 11.  Quem imperator illi legioni praefecit?  Publius illi legioni pracerat. 12.  Cum esset Caesar in citeriore Gallia, crebri ad eum[2] rumores adferebantur litterisque quoque certior fiebat Gallos obsides inter se dare.

II. 1.  The Gauls will make war upon Caesar’s allies. 2.  We heard that the Gauls would make war upon Caesar’s allies. 3.  Publius did not take part in that battle. 4.  We have been informed that Publius did not take part in that battle. 5.  The man who was in command of the cavalry was wounded and began to retreat. 6.  Caesar did not place you in command of the cohort to bring[3] disaster upon the army.