From what I understand (someone more knowledgeable may have a better answer), UTXO and Ergo’s 2 min block times make this a non-issue. At least on a layer 1 consensus level.
I know Ergo dapps can choose to use off-chain bots (ErgoDex for example), so similar issues may be more likely w/ dapps. But since dapps don’t play a part in consensus, there’d be zero possibility of chain-reorg attacks in those cases.
Account model fee system is absurd IMO and honestly I can’t wrap my head around some of the finer details, but I personally wouldn’t be at all worried.
EUTxO for the win!