Generally not in favour of paying tax on something when you don’t need to. I also wouldn’t worry about your former employer (from DC1) and management charges, as it’s probably coming straight off your fund.
I suggest talking to an advisor about combining the 2 DC schemes into a BOB/PRSA, this transfer will not trigger any tax clawback.
The first and second DB‘s probably are not worth much (due to short service) and you could move the transfer value to the same vehicle as the DCs, but you might lose some of the added DB benefits (spouse/dependants pension, inflation increases etc), and lose the ability to retire different funds at different times when you retire.