hard fork does not mean automatic split and 2 chains co-exist forevr
soft fork does not mean automatic single chain and no issues

stop using umprella terms and thn using best case scenario of soft and worse case scenario of hard.

in short:
soft=only pools vote
hard=nodes and pools vote.

then there are sub categories of good or bad of each

softfork: consensus - >94% pools no banning/ignoring of minority. result: small 5% orphan drama then one chain. minority unsynced and dead
softfork: controversial - >50% pools no banning/ignoring of minority. result: long big% orphan drama then one chain. minority unsynced and dead
softfork: bilateral split - intentionally ignoring/banning opposing rules and not including them. result: 2 chains

hardfork: consensus - >94% nodes, then >94% pools no banning/ignoring of minority. result: 5% orphan drama then one chain. minority unsynced / dead
hardfork: controversial - >50% nodes, then >50% pools no banning/ignoring of minority. result: big% orphan drama then one chain. minority unsynced / dead
hardfork: bilateral split - intentionally ignoring/banning opposing rules and not including them. result: 2 chains

if you want to talk about the ethereum style of for. that was a hard BILATERAL(intentional) split.

but also remember there is code in bip 9 to allow a soft bilateral(intentional) split too.

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to answer your question about an intentional(bilateral) split.

yes if 2 chains persist what ever funds were on the key belonging to you prior to the split will be mirrored on both copies of the chain. so yes 5btc on chain A and 5btc on chain B.

as for the 'value' or 'usability' of each, is dependant on who recognises or uses which chain.
EG if no one uses chain B then you cant really 'spend' the B chain coins because no one accepts them.