This is possible, yes. There’s an option for customizing the reset behavior when loading a log file. It can be found under ‘Tools | Option > Logs and Restore’. Just set the option to ‘Never reset Console’ (or ‘Ask for Console reset’) and the old log entries of file A won’t be removed when loading file B.
Then, to sort the log entries, you can use the ‘File | Sort Log’ dialog.
As a side note, as an alternative to merging the log files in the Console, you can also use the SmartInspect Router service application to let multiple processes log into one combined log file (I assume you are merging log files because you have multiple processes each logging into one log file, is this correct?).