$arr = [];
$arr[] = MyModelOne::find()->limit(20)->asArray()->all();
$arr[] = MyModelSecond::find()->limit(20)->asArray()->all();
for($i = 0; $i < 20; $i++){
if(isset($arr[0][$i]['title']) and isset($arr[1][$i]['title'])){
echo $arr[0][$i]['title'];
echo $arr[1][$i]['title'];
}else{
break;
}
}