Voice examples:
    Active:
        Kullupoku gulride tuddupogu zůgůtasaobo.
        Kullu=po=ku  gul-ride tuddu=po=gu zů=gůta=sao=bo
        bee=ADDRESS=ERG mark-paper[ABS] bear=ADDRESS=DAT PRXPST=give[IND]=A3A=P3I
        Bee gave a letter to Bear.
    Dative-passive: (simplified gloss, [brackets] mark removable elements)
        Půt zůgůtasaobo tuddupoku gulride [kullupoga].
        Půt zůgůtasaobo tuddupo=ku gulride [kullupo=ga]
        DPV PRXPST:give:A3A:P3I bear:ADDRESS=ERG mark:paper [bee:ADDRESS=PEG]
        Bear got a letter [from Bee].
		
		Gůslonamsu půt zekůstalaogadu roṙ nimtif stůllaotifga.
		Gů.slonam.su půt ze.ků.stalao.ga.du roṙ nim.tif stůllao.tif.ga.
health.be:DEO.P2p name-NPT. CONT.hope:DEO.A1pI DPV PP.HAB.affect:SBJ.A2p.P3pD too bad.D situation.D.PEG
		I hope that you are not too badly affected by the overall situation.
    Passive:
        Nad zůgůtaza gulride tuddupogu [kullupoga].
        Nad zůgůta=za gulride tuddupogu [kullupoga].
        PSV PRXPST:give=A3I mark:paper bear:ADDRESS:DAT [bee:ADDRESS:PEG]
        A letter was given to Bear [by Bee].
    Passive dative-passive:
        Nad půt zůgůtaza gulride [tuddupoga].
        Nad půt zůgůtaza gulride [tuddupo=ga]
        PSV DPV PRXPST:give:A3I mark:paper [bear:ADDRESS=PEG]
        A letter was gotten [by Bear].

While in all of these sentences, the verbs could grammatically go at either the end or the beginning, when voices are involved, VSO order is much more likely than SOV (in active-voice sentences VSO is slightly marked). This is partially because the voice particles (which are strongly bound phrasally with the verb) convey information that affects the semantic structure, but also because noun phrases in cases other than ergative, absolutive, and dative (in this case, the noun case of note is pegative) are typically found after the core elements of the sentence, but verbs strongly like to be peripheral. So the possible arrangements are (using C (‘core’) to refer to S, O, and indirect/dative all taken together, and X to refer to any other NP) VCX, CVX, and CXV (technically, Firen has free word order (except that ergative must go before absolutive with nothing between) so other variations are also possible, like XVC or VXC, but they are very marked) and of those three, VCX is the only one with a peripheral verb that isn’t separated from its arguments, and therefore feels most neutral.

In summary, Firen prefers, in order: CV, VC, VCX, and anything else is rare.