What is proportional one lot minimum allocation?

Lots/Amounts in the group order will be distributed in proportion to the maximum number of lots that can be open on individual participating accounts, but each account with sufficient usable margin will receive at least one lot. Example:

Managed Acct X has Equity = 5,045,175.81
Managed Acct Y has Equity = 52,383.21
Group Acct Z: when we open a position for 2 lots Acct X gets 1 lot, Acct Y gets 1 lot
When we open a position for 5 lots Acct X gets 4 lots, Acct Y gets 1 lot