well if your opponent has 100 lawyers, especially lawyers who are well-versed in different areas of the law they are able to make a more varied range of arguments than your one lawyer is, your one lawyer has to respond to those arguments and say why they are wrong or not relevant in your case or risk losing because of the existence of a particular argument, therefore your one lawyer has to do a lot of work that they might not have the expertise to do well or the time to do at all. Furthermore your opponents 100 lawyers may be more cost effective than your one, depending on the contract they have with the firm. Finally the 100 lawyers can take the time to file paperwork etc. that your lawyer has to respond to or again risk losing for not responding to some piece of paperwork. Finally when your sitting in that courtroom for a day that is a day when you will not be innovating and you will not get any money for the time you took off, courtroom days are not few and far between and your opponents 100 lawyers can spend their time making sure you have more courtroom days than you can afford.