How to resize legend in ggpubr

I have the following code:

T<-as.data.frame(matrix(0,11,2))
T$V2<-T$V2+1
colors <- c("V1" = "blue", "V2" = "red")
A<-ggplot(T,aes(x=seq(-5,5)))+
  #geom_smooth(aes(ymin=Treat-Treatse,ymax=Treat+Treatse),colour='blue')+
  geom_line(aes(y=V1,color="V1"))+
  geom_point(size=2,aes(y=V1,color="V1"))+
  geom_line(aes(y=V2,color="V2"))+
  geom_point(size=2,aes(y=V2,color="V2"))+
  labs(x='Yadayada',y='Dumdedum',color="Legend")+
  scale_color_manual(values = colors)+geom_vline(xintercept=0,linetype='dashed',col='blue')+
  scale_x_continuous(breaks=seq(-5,5),labels=c('-5','-4','-3','-2','-1','0','1','2',
                                               '3','4','5'))+theme_classic()+
  ggtitle('Example')
B<-ggplot(T,aes(x=seq(-5,5)))+
  #geom_smooth(aes(ymin=Treat-Treatse,ymax=Treat+Treatse),colour='blue')+
  geom_line(aes(y=V1,color="V1"))+
  geom_point(size=2,aes(y=V1,color="V1"))+
  geom_line(aes(y=V2,color="V2"))+
  geom_point(size=2,aes(y=V2,color="V2"))+
  labs(x='Yadayada',y='Dumdedum',color="Legend")+
  scale_color_manual(values = colors)+geom_vline(xintercept=0,linetype='dashed',col='blue')+
  scale_x_continuous(breaks=seq(-5,5),labels=c('-5','-4','-3','-2','-1','0','1','2',
                                               '3','4','5'))+theme_classic()+
  ggtitle('Example')
get_legend<-function(a.gplot){
  tmp <- ggplot_gtable(ggplot_build(a.gplot))
  leg <- which(sapply(tmp$grobs, function(x) x$name) == "guide-box")
  legend <- tmp$grobs[[leg]]
  return(legend)}
legend<-get_legend(B)
ggarrange(arrangeGrob(A+theme(legend.position="none"),
                      B+theme(legend.position="none")
                      ,nrow=1),legend, 
          nrow=2,heights=c(10,2))

It generates the following plot:

I was wondering if there was a way to resize the legend within the common plot(relative to the two figures in the common plot) that is generated above? The 'heights' function doesn't seem to resize the legend itself, merely the amount of space it takes up.