Tailor-made rules made for one party's interest, nice.
In one of the past cavalry leagues, hosted by Kanade Tachibana, there used to be a "one invite rule" which allowed each regiment to add one person from regiments outside of the league to their roster and have their help during the competition. The explaination was similiar as the one we get now: "we don't want to leave players out" (during that season, a portion of competetive players were left out, mainly due to the famous Nr. 3 Branderburgischeblablalblaregiment not entering). Oddly enough, Erik was very opposed to this feature at the time so it's ironic to see him now announce a rule which loosens the legitimacy of rosters even more, with similiar excuse being given for it's implementation. Ironic but not surprising.
If this rule will be allowed to pass by regimental leaders and if we will see what we all expect to see as it's direct conseqence then, uhm... well, nothing, to be honest. Whoever has to lose will lose anyway and it's not like the rules of this league have any credit left to forfeit.