I would not be a fan of overcapitalising accounts.

better keep most of your money on deposit, and only transfer into brokerage sufficient funds to cover margin. e.g if trading 20k leave 18k on deposit and put 2k in brokerage. Most countries guarantee client funds up to a limit, so cna factor that in too. i.e. if country will guarantee 20k client funds and you wish to have 100k with brokers use 5 different brokers!