Re-using first public address with multisig key... secure?

If an association uses a 3-of-5 multisig key and wants a public address that shows all deposits... are they limited to making deposits into the first public address?

I'm familiar with how HDeterministic wallets work and that they are more secure when not re-using addresses... but if the association wants ONE public address that they can see their balance, they would need to re-use the first address in the HD wallet, correct? What's the REAL loss in security by doing this?